RESIDUE IN AN AQUEOUS SAMPLE

FIELD AND BACKGROUND OF THE INVENTION

The instant invention, in some embodiments thereof, is directed to the detection of chemical or biological contaminants in a liquid sample. This International application claims priority from US Provisional Patent Application 62/024,475 filed 15 July 2014.

SUMMARY OF THE INVENTION

It is a purpose of the present invention, in some embodiments, to provide methods and devices for detecting the presence of at least one predetermined residue in an aqueous sample through the action of causing a portion of the sample to flow through a hydrophobic element while in proximity to a single electrode associated with an electrical metering device.

The invention includes a device for identifying the presence of a chemical or biological residue in a liquid sample, including: at least one unpowered electrode; an electrical metering device adapted to be in electrical communication with the electrode; at least one hydrophobic liquid delivery element placed in proximity to the electrode and adapted to receive a portion of a liquid sample; a fluidic element adapted to enter the portion into the delivery element and further adapted to remove the portion from the liquid delivery element at a later time; a computing element in electrical communication with the electrical metering device and adapted to receive electrical signals recorded by the electrical metering device; software adapted to run on the computing element and adapted to determine a presence or absence of a chemical or biological residue in the liquid sample as a function of the electrical signals; a display element in electrical communication with the computing element and adapted to show a user information regarding a presence or absence of the chemical or biological residue in the liquid sample; and, a source of electrical energy adapted to provide electricity to the electrical metering device, the computing element and the display element.

In one aspect of the device, the liquid delivery element is realized as pipette tip, a syringe, a syringe needle, tubing, a pipe, a faucet, a toilet, or a pipette. In another aspect of the device, the liquid sample is realized as well water, mineral water, drinking water, tap water, lake water, river water, fresh water, stored water, bottled water, water produced by reverse osmosis, distilled water, deionized water, defrosted snow or ice, chemically- treated water, grey water, sewage, waste water, circulation water, reclaimed water or rain water.

In another aspect of the device, there is additionally a communication element adapted to transfer data from the computing element to a mobile electronic device.

In another aspect of the device, the proximity is measured from 0 to 20 centimeters between the electrode and the liquid delivery element.

In another aspect of the device, the at least one liquid delivery element is coated in part with binding agents adapted to bind at least one predetermined chemical or biological residue at some level of specificity.

In another aspect of the device, the fluidic element is adapted to eject the portion in a manner so that the portion passes by but does not come into contact with the electrode.

The invention includes a method for determining the quality of a liquid sample, including the following: providing an unpowered electrode attached to an electrical metering device; providing a hydrophobic pipette tip attached to a bi-directional liquid pump, wherein the pipette tip is adapted to take up and eject a liquid sample; providing a liquid sample; taking up a portion of the liquid sample with the pump via the disposable pipette tip; causing the portion of the liquid sample to flow in a predetermined direction out of the pipette tip, wherein the portion is adapted to pass by but not contact the electrode; recording a plurality of electrical signals with the electrical metering device when the portion is flowing out of the pipette tip; analyzing the electrical signals with a computing element; determining a presence or absence of a contamination in the liquid sample as a function of the electrical signals; and, displaying for a user a determination of the presence or absence of the contamination in the liquid sample.

In one aspect of the method, there is additionally a step of attaching the electrical metering device to a portable electronic device. In another aspect of method, the determining involves comparing the electrical signals with predetermined electrical signals previously recorded for aqueous samples lacking and containing predetermined chemical or biological contaminants.

The invention further includes a device for recording electrical signals generated by a liquid flowing relative to a solid element, including: at least one electrode; an electrical metering device in electrical communication with the electrode; a solid element adapted to contact a liquid material; a fluidic device adapted to cause the liquid material to flow relative to the solid element; and, a display for presenting information about a composition of the liquid material.

In another aspect of the device, the liquid is water and the composition relates to presence or absence of heavy metals, organic compounds or biological materials in the water.

In another aspect of the device, the solid element is realized as hollow and plastic.

In another aspect of device, the electrode is realized as a plurality of electrodes.

In another aspect of the device, the display is selected from a plurality of LED lights, a sound, a buzzer, lights, a graphical user interface, a touchscreen, or any combination thereof.

In another aspect of the device, the device is adapted to send data to a smartphone.

Unless otherwise defined, all technical and/or scientific terms used herein may have the same general meanings as commonly understood by a practitioner of ordinary skill in the art to which the invention pertains. An electrical meter or electrical metering device may include but not be limited to a voltmeter, ammeter, resistance meter, Hertz meter, CPS meter, oscilloscope, dielectric measurement unit, EMF measuring device, or other device capable of receiving and/or processing an electrical signal or input, or a combination thereof. "Conductor" and "electrode" may have their generally understood meanings as known in the electrical arts. An electrode for the instant invention is generally unpowered, meaning that no current or voltage is applied to said electrode, though powered electrodes may be used in embodiments of the invention.

"Hydrophobic" as applied to solid materials such as pipette tips may generally refer to materials that have water contact angles of 60 degrees or higher when measured with a contact angle goniometer. An "aqueous solution" may generally be any water-based solution that may possibly include salts or other materials. A "liquid delivery element" may generally refer to an element capable of taking up and then discharging a liquid sample into or in the vicinity of an electrode, wherein said electrode is not wetted. Pipettes, microliter fluid dispensers, microfluidic systems, and syringes are non-limiting examples of liquid delivery elements. A "mobile computing device" may be a cellular phone, a smartphone, tablet computer, mobile computing element, laptop computer or other appropriate computing element. "Residue" may generally refer to bacterial or chemical material present in and the subject of detection in an aqueous solution. Residues may include bacteria, viral particles, predetermined chemical or chemical classes, metals, small molecules, macromolecules, or other predetermined materials or groups of materials. "Binding agents" may generally refer to antibodies, nucleic acids, receptors or other molecules/macromolecules that may bind or interact with a predetermined target or group of targets with some level of specificity of interaction. An analyte, residue or target may generally be a material that is the subject of detection and/or quantification. Bacteria and viruses as well as heavy metals and organic pesticides are non-limiting examples of potential residues for the instant invention. "Plastic element" may generally refer to any material made of plastic or polymer. A preferred plastic element is a polypropylene tip of a micro-pipette.

"Quality" with respect to water or other liquids may generally refer the absence or presence of contaminants. A good quality sample may lack predetermined biological and/or chemical contaminants or residues, whereas a low quality sample may have biological and/or chemical contaminants or residues. Such contaminants may be defined by local, national, international, personal, or industry standards.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced. It is noted that similar elements in various drawings will have the same number, advanced by the appropriate multiple of 100. In the drawings:

FIG. 1 shows a flowchart of a method of the invention;

FIGS. 2 - 4 show photographs of a device adapted to implement a method of the invention; FIGS. 5 - 8 show results from experiments run with the device previously referenced; FIG. 9 shows a schematic view of an alternative embodiment of the instant invention;

FIG. 10 shows results of experiments run with the embodiment shown in FIG. 9;

Fig. 11 shows some data regarding contaminant levels in drinking water;

FIG. 12 shows an embodiment of the instant invention adapted for drinking water quality analysis;

FIG. 13 shows data relating to the embodiment shown in FIG. 12;

FIG. 14 shows a photograph of a component associated with a personal water quality testing device;

FIG. 15 shows a picture of a device based on an embodiment of the instant invention; and,

FIG. 16 shows output signal from the device shown in FIG. 15.

DESCRIPTION OF SPECIFIC EMBODP ENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to methods and devices for detecting the presence of chemical and/or biological residues in a liquid by virtue of passing a portion of said liquid through a hydrophobic element in the vicinity of a single electrode.

When an aqueous sample is taken up in a plastic pipette tip, triboelectric phenomena leave the water positively charged and the tip negatively charged. If there are chemical and/or biological residues located in the water, then they too may interact with the plastic pipette tip; these materials additionally interact with water, such interactions possibly affecting the way water itself interacts with the disposable tip. When force is applied to move or eject the aqueous sample from the pipette tip, the above-mentioned interactions are necessarily changed or broken. This change in interactions implies a release of energy, said energy being associated with the water-tip electrical interactions established immediately prior to sample ejection. Some of the released energy may be in the form of electromagnetic radiation that can be detected with an appropriate unpowered electrode or antenna. The instant invention, in some embodiments, is founded on electrical effects of ejecting a liquid sample from a hydrophobic (generally plastic) element in non-contact proximity to a single, unpowered electrically-conductive electrode. It has been seen over several thousand experiments that ejecting a small sample of water or other liquid near a conductive electrode attached to a voltmeter or similar element causes a reading in the voltmeter or the like, even if there is no contact between the water or other liquid and the electrode in use. The ejected liquid never touches the electrode which remains dry throughout the experiment. This is a major advantage of the instant invention, as electrode does not need to be cleaned or replace. Additionally, there are no reagents that must be added for testing. When liquid does not flow, there is no signal whatsoever, s

The elements generally required for a successful identification of contaminants which may include pathogenic bacteria, proteins, heavy metal ions and small organic molecules, are generally the following:

*An aqueous sample, which may generally be a drinking water sample;

*A pipette with a disposable tip or similar element;

*An EMF detector a with a single passive electrode associated with it;

*A computing element adapted to receive data from detector and optional software associated with the computing element for interpretation of results;

*A source of electrical energy for the detector and computing element; and,

*A display element for showing a user what the sample quality is, where quality is defined as absence or presence of biological or chemical residues, said residues preferably not present in said sample.

In the embodiments and examples below, the sensor is described in greater detail. It is understood that other embodiments not formally described are possible without deviating from the spirit and intent of the instant invention.

First Embodiment Attention is turned to FIG. 1 which shows a flowchart for a method of the instant invention. The invention includes a method for determining the quality of a liquid sample, including the following: providing an unpowered electrode attached to an electrical metering device; providing a hydrophobic pipette tip attached to a bi-directional liquid pump, wherein the pipette tip is adapted to take up and eject a liquid sample; providing a liquid sample; taking up a portion of the liquid sample with the pump via the disposable pipette tip; causing the portion of the liquid sample to flow in a predetermined direction out of the pipette tip, wherein the portion is adapted to pass by but not contact the electrode; recording a plurality of electrical signals with the electrical metering device when the portion is flowing out of the pipette tip; analyzing the electrical signals with a computing element; determining a presence or absence of a contamination in the liquid sample as a function of the electrical signals; and, displaying for a user a determination of the presence or absence of the contamination in the liquid sample.

In one aspect of the method, there is additionally a step of attaching the electrical metering device to a portable electronic device. In another aspect of method, the determining involves comparing the electrical signals with predetermined electrical signals previously recorded for aqueous samples lacking and containing predetermined chemical or biological contaminants.

An unpowered electrode in the instant embodiment is generally round, may be hollow in it middle, may generally be coated with gold, and in some embodiments may either be wound around the pipette tip or be realized as a plurality of unique electrodes wound around or in non-contact proximity to the the pipet tip. A pipette tip may generally be selected from disposable polypropylene pipette tips traditionally used in laboratories whose volumes generally ranges from 0.5 microliters to 5 milliliters. Pipette tips may be coated internally with binding agents or the like to aid in identifying predetermined target chemical or biological residues. A bi-directional pump may generally take up and further release a sample taken into the pipette tip. The pump may be human, computer, or otherwise activated for taking up and releasing sample. It is understood that one may make a reading while taking in a sample, though output signal is more consistent when measurements are made on samples being forced out of tip.

In typical samples, 10-100 microliters of sample are taken up via the pump into a pipette tip adapted to hold 200 microliters. The sample may be immediately ejected or alternatively allowed to sit for a predetermined time in the tip prior to ejection. Ejection of sample causes generation of EM waves from broken water interactions with tip as the water leaves, and these waves are identified by the electrical metering device. If a residue sticks to the inner side of the plastic tip, output is reduced; clean sample gives higher amplitude output signal (generally measured in unit of volts) than do samples having undesirable chemical and/or biological residues.

Attention is turned to FIG. 2 which shows a photograph of a device 200 built for implementation of the instant method. The device 200 is adapted to include provision for a power source realized as batteries (not shown so as to show battery holder 205). The device 200 also includes a digital EMF meter 218 component adapted to make readings in microvolts or higher. The device includes a single round gold electrode 210, the element 215 next to it being used for measuring and cancelling background EMF readings; in the instant embodiment, only a single unpowered electrode 210 was employed by the meter 218 associated with the device 200. The gold electrode 210 is adapted to hold a pipette tip in its open middle. The device includes a power switch 220 and a start button 225 that is adapted to start a measurement when a portion of sample is ejected from a pipette tip sitting within the gold electrode 210. Nine LED lights 250 (3 green/3 yellow/3red) are adapted to light up according to outputs and serve to alert a user as to the status of an aqueous sample tested. A typical test from sample ejection to LED 250 illumination is around 5 seconds. A USB cable 240 allows for optional transmission of data from the device 200 to a computer (not shown) for data storage and analysis.

FIG. 3 shows an alternative photographic view of the device 300 in which a pipette tip 330 is placed within the gold electrode 310. To the right of the device 300 is a pipette 345 adapted to hold the pipette tip 330 which is made of polypropylene and is considered one-use/disposable. FIG. 4 shows another view of the pipette tip 430 (shown without pipette for convenience) sitting in the single gold electrode 410. Ejection of sample from the tip appears to generate EM waves that impinge on the electrode 410 and cause motion of electrons within the electrode. Those electron motions are detected by the EMF metering component of the device and a voltage-based signal is recorded and analyzed. The outcome of the signal is relayed to the LED lights 450 used as display on the device 400.

The efficacy of the instant method may be seen in FIGS. 5 - 10. FIG. 5 shows data for the detection of lead ion (Pb ³⁺ ) in water. Lead is an extremely dangerous potential water contaminant, especially for developing children. In FIG. 5, which is read from left to right are five data sets collected consecutively with a new pipette tip employed for each sample. In each experiment, 70 microliters of a solution provided by Strauss Water, Ltd (Petah Tikvah, Israel) was taken up in a blue 1000 uL disposable pipette tip (Tamar Science, Abu Ghosh, Israel). The tip with sample was placed in the electrode on the device (as previously shown and described in previous figures). The start button of the device was activated and the pipette (Eppendorf, lOOOuL) ejector button was manually depressed to evacuate liquid from the tip. The liquid was released into a disposal cup. During the release of aqueous sample from tip, the electrical metering component of the device read voltage readings coming from the electrode. At no time was there ever contact between the liquid and the electrode, and in some embodiments, the tip may be as far as 20 centimeters from the electrode, and readings (albeit smaller) may be recorded. Automatic sample uptake and/or release is possible in some embodiments.

FIG. 5 from left to right shows clean water (from reverse osmosis of tap water) A; same water with 5 ppb lead ion, B; 10 ppb lead ion, C; 50 ppb lead ion, D; and, 100 ppb lead, E. -2,000 uV is background value in absence of sample or sample ejection, even if present in tip in electrode. Sample A, clean water shows a single peak that terminates at 4,000 microvolts (uV), the upper limit of device detection. 5 ppb of lead, which is legal according to US standards, shows the 4,000 microvolt peak but also includes a small peak that reaches down to 1,500 microvolts (similar to a peak in test A). 10 ppb lead ion, which is the threshold of contaminated water according to NSF standards, introduces a new peak that goes down to 500 microvolts. 50 ppb shows the same peak, but with greater effect. Finally, 100 ppb lead shows a new 4,000 microvolt peak, independent of the water peak.

FIG. 5 data show that within seconds a user— either a lab technologist or a private consumer, for example— can see a difference in water interaction with a disposable tip as a function of the presence of an unwanted dangerous heavy metal ion. The 5 ppb sample shows no great difference with lead-free water, but from 10 ppb and higher, the differences are quite noticeable and "bad" water with high lead presence would cause the red LED's of the device to go off (instead of the three green LED's for clean or marginally contaminated water). Y-axis is measured in microvolts, while X-axis is reading numbers, approximately 100 readings per second sampling rate.

FIG. 6 shows detection of pathogenic E. coli 0157:H7 bacteria in lab water (triply distilled, deionized, Chemistry Labs, Hebrew University, Jerusalem, Israel). Sample A is lab water and shows a peak at 3000 uV and a major peak at 4,000 uV. Sample B includes about 50 CFU's of pathogenic bacteria E. coli 0157:H7 per milliliter. There are two small peaks under 3,000 uV and a very large negative peak reaching down to around 900 uV. Photograph 680 shows a MacConkey agars plate of sample B, which shows a very small number of E. coli present. The plate required 8 hours for development; the testing of sample B was over in less than 5 seconds. Software may be employed to identify output patterns and associate them with specific contaminants.

Attention is turned to FIG. 7 which shows results from application of the instant method. Signal A represents a background test by the device in the absence of tip or sample. A background test is generally run without tip in electrode, though one may run a background test with tip sitting in electrode, if the contents of the tip are left in place: there is no signal beyond background 2,000 uV if sample is not ejected or caused to flow through or out of tip. Signal B represents Jerusalem tap water, two peaks seen, one at around 3,000 uV and the other reaching 4,000 uV, the limits of device voltmeter sensitivity. Signal C represent nanogram/milliliter amounts of bovine serum albumin (BSA, Sigma-Aldrich, Milwaukee) in tap water. The highest peaks are less than 3,000 uV and one negative peak going down to 1,000 microvolts is recorded. The system thus shows enormous sensitivity for protein detection, something that is important for possible ricin or similar terrorist attempts to harm large numbers of people through public drinking water. Signal D represents microgram/milliliter amounts of BSA in tap water— note that signal is all but wiped out (-2,000 microvolts is the background value).

Attention is turned to FIG. 8. FIG. 8 shows a comparison of water without and with 10 ppb chloroform, a very problematic water contaminant. Signal in regions A and C are mineral water (Ein Gedi, Israel) and regions B and D are the same mineral water with diluted chloroform (Israel Chemicals, Haifa, Israel) to 10 ppb. One can see that the water samples again show a major peak reaching 4,000 uV, whereas the contaminated samples show no to negative signal.

The instant method has been incorporated into a dedicated device that has been successfully used in the detection of heavy metals, pathogenic bacteria, proteins and small organic molecules in lab water, tap water, and mineral water. Detection times are measured in seconds, and the system as no contact between sample and single electrode employed in detection. Detection sensitivity is in the range as mandated by U.S. law.

It is understood and appreciated that one may place the pipette tip in proximity to an electrode prior to taking up sample; the order as described is no mandatory. Additionally or alternatively, pipette tip does not have to be in the middle of the electrode; readings may be recorded with electrode if sample ejection from tip occurs within 20 centimeters of electrode. Second Embodiment

The invention includes a device for identifying the presence of a chemical or biological residue in a liquid sample, including: at least one unpowered electrode; an electrical metering device adapted to be in electrical communication with the electrode; at least one hydrophobic liquid delivery element placed in proximity to the electrode and adapted to receive a portion of a liquid sample; a fluidic element adapted to enter the portion into the delivery element and further adapted to remove the portion from the liquid delivery element at a later time; a computing element in electrical communication with the electrical metering device and adapted to receive electrical signals recorded by the electrical metering device; software adapted to run on the computing element and adapted to determine a presence or absence of a chemical or biological residue in the liquid sample as a function of the electrical signals; a display element in electrical communication with the computing element and adapted to show a user information regarding a presence or absence of the chemical or biological residue in the liquid sample; and, a source of electrical energy adapted to provide electricity to the electrical metering device, the computing element and the display element.

In one aspect of the device, the liquid delivery element is realized as pipette tip, a syringe, a syringe needle, tubing, a pipe, a faucet, a toilet, or a pipette. In another aspect of the device, the liquid sample is realized as well water, mineral water, drinking water, tap water, lake water, river water, fresh water, stored water, bottled water, water produced by reverse osmosis, distilled water, deionized water, defrosted snow or ice, chemically-treated water, grey water, sewage, waste water, circulation water, reclaimed water or rain water. In another aspect of the device, there may additionally be a communication element adapted to transfer data from the computing element to a mobile electronic device. Such an element may include WiFi, Bluetooth, IR or other technology for transferring data from a device to a smartphone or the like. In another aspect of the device, the proximity is measured from 0 to 20 centimeters between the electrode and the liquid delivery element. In another aspect of the device, the at least one liquid delivery element is coated in part with binding agents adapted to bind at least one predetermined chemical or biological residue at some level of specificity. In another aspect of the device, the fluidic element is adapted to eject the portion in a manner so that the portion passes by but does not come into contact with the electrode. A chemical residue may be any chemical material. A biological residue may be any biological substance including but not limited to bacteria, viruses, virus particles, spores, fungi, and any natural products including but not limited to proteins, nucleic acids, amino acids, fats, vitamins, or biological markers. Liquid may be any liquid including but not limited to water-based solutions. Organic solvents and liquids may be employed in the instant embodiment. The single electrode is generally a conductive material attached at one end to the electrical metering device. "Passive" with respect to electrode may generally mean that no voltage, current or other signal is applied by the metering device or other source to the single electrode. The metering device may measure one or a plurality of electrical signals generated during an analysis of the liquid under study. A computing element may generally be an element based on a processor. The computing element may be dedicated to the device or may be realized as part of a mobile computing device such as a smartphone, watch, tablet computer or Google Glass or the like. Software may be realized as a plurality of software elements and they may be associated with the computing element or be located at another location and accessible to the computing element. Examples of display elements include LED's, graphical user interfaces, touch screens, computer screens, smartphone screens, or other display elements adapted to provide information to a user as to the presence or absence of chemical and/or biological residues in the liquid. The information may be general such as that there is some contamination or it may be specific, identifying the offending material such as a specific bacterial strain or heavy metal.

Attention is turned to FIG. 9. A device 900 for detecting chemical or biological contaminants in a liquid sample includes an electrical metering element 960 attached to a conductive electrode 910. The metering element 960 is additionally in electrical communication with a computing element 970 as well as a display 980. An energy source 905 is also provided and is adapted to provide electrical energy to the metering element 960, computing element 970 and display 980. The energy source 905 may include batteries, local electricity (wall socket), hand-driven electricity or any other relevant power source. Software may be run on the computing element 970 to interpret electrical signals recorded by the metering element 960 when a portion 995 of a liquid sample is ejected 999 from a pipette tip 930 or other liquid delivery element. The tip 930 may be spaced X centimeters from the electrode 910, wherein X is generally between 0 and 20 centimeters. 0 centimeters implies that the electrode 910 contacts the pipette tip 930— but the electrode remains dry; there is never contact between the liquid portion 995 and the electrode 910. The portion 995 may optionally be moved within the tip 930 or similar element without actually ejecting 999 outside of the tip (moving from one portion of a tip 930 to another).

FIG. 10 shows data for vodka analysis. The data were collected from an experimental setup as described in the instant embodiment, with distance between pipette tip and electrode of 3.5 centimeters. Signal A includes three consecutive experiments with 70 microliters of Smirnoff (England) vodka, 48% alcohol each. Signal B is three consecutive experiments with 70 microliters of 50% diluted (with water) vodka each. As ethanol concentration decreases, water signal increases, which allows for detection of diluted vodka sample.

Third Embodiment

The invention further includes a device for recording electrical signals generated by a liquid flowing relative to a solid element, including: at least one electrode; an electrical metering device in electrical communication with the electrode; a solid element adapted to contact a liquid material; a fluidic device adapted to cause the liquid material to flow relative to the solid element; and, a display for presenting information about a composition of the liquid material.

In another aspect of the device, the liquid is water and the composition relates to presence or absence of heavy metals, organic compounds or biological materials in the water. In another aspect of the device, the solid element is realized as hollow and plastic. In another aspect of device, the electrode is realized as a plurality of electrodes. In another aspect of the device, the display is selected from a plurality of LED lights, a sound, a buzzer, lights, a graphical user interface, a touchscreen, or any combination thereof. In another aspect of the device, the device is adapted to send data to a smartphone.

Drinking water safety is of paramount importance for virtually every country. FIG. 11 shows a partial list of possible contaminants and their concentration limits in drinking water. The instant embodiment is directed towards the detection of potential hazards in water including but not limited to bacteria, viruses, fungi, small organic compounds, heavy metals, pesticides, drugs, and biological materials. The instant embodiment may be employed as an early-warning system, defining water as acceptable for use or unacceptable, without specific details as to chemical and/or biological residue(s) present. Alternatively and additionally, the instant embodiment may be employed singly or in a multiplexed mode to detect a specific or a plurality of specific problematic components in a water sample. In some embodiments, a pipette tip or similar liquid delivery vehicle may be chosen for its materials or properties or may be coated with antibodies, receptors, DNA, or other materials in order to aid in defining a specific material or class of material present in a water sample.

The importance of the instant embodiment lies in the ability of every consumer to test his/her water. In advanced countries where water testing is mandatory, all testing occurs at the point of water production— in the case of municipal water, than can be tens of miles or more from a consumer. Nothing is taken into account with respect to broken, rusty or old pipes between the producer and the consumer. In less advanced countries, there may be no or little oversight of water quality. The instant embodiment may be made in a pen-style or other user- friendly format for easy use. As the response and output on the display occurs within seconds, consumers can know if the water is safe for drinking or not. In some embodiments an appropriate device may communicate with a mobile electronic device through a cable or wirelessly.

Attention is turned to FIG. 12. A device 1200 for detecting chemical or biological contaminants in a drinking water sample includes an electrical metering element 1260 attached to a conductive electrode 1210. The metering element 1260 is additionally in electrical communication with a computing element 1270 as well as a display 1280. An energy source 1205 is also provided and is adapted to provide electrical energy to the metering element 1260, computing element 1270 and display 1280. Software may be run on the computing element 1270 to interpret electrical signals recorded by the metering element 1260 when a portion 1295 of a drinking water sample is ejected 1299 from a pipette tip 1230 or other liquid delivery element. The tip 1230 may be spaced X centimeters from the electrode 1210, wherein X is generally between 0 and 5 centimeters, though it may be greater. 0 centimeters implies that the electrode 1210 contacts the pipette tip 1230; there is never contact between the liquid portion 1295 and the electrode 1210.

FIG. 13 shows results of drinking water testing. Samples 1 and 2 are Petah Tikva (Israel) tap water, sample 1 treated by a charcoal filter and sample 2 treated by reverse osmosis. Each sample showed between 1000 and 2000 non-coliform CFU's per milliliter by plating. Samples 3 - 6 show samples having 2000, 500, 17 and 2 CFU's per milliliter of E. coli, respectively. As one can see, the presence of coliforms in samples 3 - 6, even at very low bacteria concentration, leads to removal of the 4,000 uV peak for water and adds two negative peaks reaching 1,500 and 1,000 uV values. The first samples are amenable for drinking and the large 4,000 uV peak is representative of the same. The small amount of contaminant E. coli identifies the samples as being adulterated and in need of treatment of disposal.

FIG. 14 shows the electronics associated with a miniature detection device based on the instant embodiment. The PCB 1498 next to the US quarter is adapted to detect biological and chemical residues in water and report the same. The PCB 1498 includes an electrode 1410 as well as a second electrode (not shown) on the opposite side; the second electrode measures and cancels EM noise. Attention is turned to FIG. 15, where the PCB 1598 previously described was incorporated into a device 1500 in which an electrode 1510 (covered in waterproof coating) is a fixed distance of 4 millimeters from a 0.5 - 10 microliter disposable pipet tip 1530. A fluidic element 1590 brings 40 microliters of liquid into the pipet tip 1530 through the agency of a button 1591. Release of the button 1591 causes liquid to egress from the pipet tip 1530 and simultaneous activation of electrical measurements in the electrode 1510. Electrical signals are collected and analyzed by a processor (not visible) associated with the device 1500 and a LED display 1550 shows if liquid is safe for consumption. In this figure, a red LED 1550 is activated, suggesting that a water sample tested is not appropriate for human consumption. The device 1500 includes either internal or external battery power as well as an optional USB port 1597 for delivery of data to a computing device 1509, an output of which is shown in FIG. 16. The large negative peak A is associated with clean water, while E. coli contaminated water is associated with flat output B. Y- axis is a measurement in voltage units while X-axis shows reading number.

It is expected that during the life of a patent maturing from this application, additional systems for measuring residues in liquid samples, and the scope of the term of the invention is intended to include all such new technologies a priori.

As used herein the term "about" refers to□ 10 %.

The terms "comprises", "comprising", "includes", "including", "having" and their conjugates mean "including but not limited to".

The term "consisting of means "including and limited to".

The term "consisting essentially of means that the, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure. It is understood that the instant invention may be fully or partially integrated into a plurality of different devices including food safety or human diagnostic equipment. It is understood that embodiments of the instant invention could allow for measurement of many samples either sequentially or simultaneously, and the single experiments shown in the figures above is for convenience only. One obvious embodiment would be to use a compass or similar device, wherein the moving water or other liquid would cause a displacement of a metallic or magnetic element. The amount of displacement would be reflective of the state of the liquid and the presence or absence of any predetermined residues.

As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

Whenever a numerical range is indicated herein, it is meant to include any cited Humeral (fractional or integral) within the indicated range. The phrases "ranging/ranges between" a first indicate number and a second indicate number and "ranging/ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals there between.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. The present invention could be employed for a wide variety of applications including but not limited to municipal water testing, beverage water testing, beverage testing, human diagnostics, food safety, homeland security and consumer testing of water and food products.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. It would be obvious for example that one could inject a sample into an empty container with or without a conductive element present in the container; one does not have to have a solution present in container to have a reading, though readings tend to be more consistent if one injects a sample into an aqueous solution in a portion of a container.

In previous embodiments, the liquid delivery element has been described as non- conductive; in some embodiments, the liquid delivery element, often realized as a disposable pipette tip, may be electrically conductive in part or completely. In some such embodiments, a disposable conductive polymeric pipette tip is preferred. Additionally, while embodiments generally describe injecting or ejecting sample from a pipette tip or similar liquid handling element, it is understood, that one might alternatively or additionally make a measurement with a voltmeter or similar electrical metering element while sample is being taken up into a pipette tip or the like

All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.