Method and system for detection of target molecules FIELD OF THE INVENTION

[0001] The present invention relates to detection of target molecules. More specifically, the present invention is concerned with a method and system for detection of target molecules, such as explosives, narcotics or illicit substances.

SUMMARY OF THE INVENTION

[0002] More specifically, in accordance with the present invention, there is provided a system for detecting target molecules in at least one location, comprising at least a first member comprising an air distributor, at least a second member comprising an air intake, and at least one nanofiber sensor, wherein the air distributor directs an airflow to the air intake across the at least one location, the air intake collects the airflow and directs the airflow to the nanofiber sensor, the nanofiber sensor receiving the airflow and processing the airflow to detect occurrence of the target molecules therein.

[0003] There is further provided a method for detecting target molecules, comprising generating an airflow across a location, collecting the airflow, and directing the collected airflow to a nanofiber sensor configured to detect the target molecules.

[0004] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In the appended drawings:

[0006] FIG. 1A is a front cross-secti on a l view of a system according to an embodiment of an aspect of the invention;

[0007] FIG. 1 B is a perspective view of the system of FIG. 1 A;

[0008] FIG. 2 is a front view of a system according to an embodiment of an aspect of the invention;

[0009] FIG. 3 is a perspective view of a system according to an embodiment of an aspect of the invention; [0010] FIG. 4A is a schematical view of a manifold of a system according to an embodiment of an aspect of the invention;

[0011] FIG. 4B is a schematical view of a se n sor u n it of a system according to an embodiment of an aspect of the invention; and

[0012] FIG. 4C is a schematical view of a se n sor u n it asse m b led with a manifold in a system according to an embodiment of an aspect of the invention.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0013] The present invention is illustrated in further details by the following non-limiting examples.

[0014] A system according to an embodiment of an aspect of the invention is shown in FIGs. 1, in the case of a space such as a corridor in a building for example, and adapted for installation on a doorframe for example. The system 10 comprises a base member 12, a top member 42, lower side members 20, 24, and upper side members 26, 40, assembled in such a way as to frame at least part of a throughway such as a doorway or an opening 44 in a wall for example. Air ducts 200 run within the members of the system 10, the top member 42 being provided with air distributors 16, and the base member 12 and lower side members 20, 24 being provided with air intakes 18. An air pump or fan module 400 may be integrated to any of the members of the system 10. The system 10 is this able to prompt an airflow fro m th e to p of the space (see arrows) generally towards the floor of the space and the air intakes 18, for recovery of the air that has t h u s crossed the distance between the ceiling and the floor of the space in this instance.

[0015] The system 10 further comprises a sensor unit 22, in air flow communication with any one of the side members 24 or 26, the bottom member 12 or the upper member 42. The sensor unit 22 may be attached to the side member as shown in FIGs. 1 for example, or remotely located.

[0016] As items or/and persons pass through the opening 44 thus framed by the members 12, 20, 24, 26, 40 and 42, particles that may be carried thereon are dislodged by an airflow originating from the air distributors 16 sending air from the top of the doorway or an opening 44, are then drawn in by the air intakes 18 located at the bottom of the doorway or an opening 44 and are directed by the air ducts 200 within the members of the system 10 to the sensor unit 22 through a manifold 52, for analysis.

[0017] The sensor unit 22 thus continuously analyses all airflow across the doorway or opening 44. When a target particle is detected by the sensor unit 22, an alarm is emitted through a user interface 48. The sensor unit 22 may communicate either wirelessly or through a wired connection to the user interface 48, which may be attached to or located near the system 10 as illustrated in FIG. 1 for example, or remotely therefrom. The user interface 48 may simply be a red light alerting detection, or a complete computer workstation displaying full information about, for example, concentration levels and particles that were identified.

[0018] The system 10 may be dismounted and taken apart rapidly. As illustrated for example in FIG. 2, the lower 24, 20 and upper 26, 40 side members may be dismounted in a telescoping relationship and then further folded by pivoting on hinge points 146 connecting the base member 12 and the lower side members 20, 24 for example. The top member 42 is shown as being be completely detachable from the upper side members 26, 40. The sensor unit 22 may also completely detach from the remainder of the system 10 as shown, so that the whole system 10 may be collapsed for ease of transportation thereof.

[0019] FIG. 3 shows a system according to an embodiment of an aspect of the invention, in a mobile platform such as a sea-container 238 for example. Air inputs 214 and air distributors 216 are located on a first side wall of the platform 238, while air intakes 218 are located on the opposite side wall. The air inputs 214 provide an air flow to the air distributors 216 for circulation across the width of the inside of the platform 238 to the air intakes 218, and then circulation to a detector 222.

[0020] The assembly 210 is weather resistant and may be provided with mounting points 232 at a base thereof, allowing it to be secured to the ground wherever it is deployed. Lifting hooks 230 may further be provided to allow lifting equipment to pick the system 210 up.

[0021] The system 210 may either be run by plugging it into a constant power supply with power plug 236 or by using an integrated battery module 234 and/or an electrical generator module 250, allowing for extended autonomy for example.

[0022] The platform 238 is provided with automatic sliding doors 228 for entry and exit at either ends thereof. The doors 228 may be controlled so that they close when analysis of the airflow within triggers an alarm as described in relation to FIGs. 1. The assembly may be designed with an energy absorbing structure adapted to contain a blast in a case an explosive is detonated within.

[0023] The ventilation system 214, 216, 218, the sensor unit 222 and the power unit 234, 236, 250 may be mounted on the inside of the container 238, thereby allowing for standard outer dimensions. Alternatively, they may be located on the outside of the transportable platform 238 as shown in FIG. 3. They may be mounted on the side as illustrated or in any other configuration, such as on top of the container 238 for example. The ventilation 214/216/218, the sensor unit 222, and the power modules 234, 236 and 250 may be detachable, stored in the container 238 during transport, and assembled on-site. [0024] FIGs. 4 show details of a sensor unit 322 (FIG. 4B), of a manifold duct 352 (FIG. 4A) and of the sensor unit assembled with the manifold (FIG. 4C), according to an embodiment of an aspect of the invention. The manifold duct 352 is used for drawing air collected from the environment, such as from across a doorway as illustrated in FIG. 1 for example, or from within a space as illustrated in FIG. 3 for example, into the sensor unit 322. The manifold duct 352 may change in terms of size, depending on the application, so as to adapt to the volume of airflow collected, while the sensor unit 322 remains the same.

[0025] The present system may be assembled in a turnkey mobile platform, a vehicle such as car, a bus, a train, or an airplane for example, or integrated into existing infrastructure such as a building.

[0026] According to an aspect of the invention, nanofiber sensors are used. A nanofiber sensor comprises nanofibers forming a mesh across an electrode pair. Target molecules in the airflow conveyed to the sensor get caught in the nanofibers. The molecules which interact with the nanofibers net either withdraw of donate electrons, thus resulting in a decrease or increase in observed current. The nanofibers are selected according to their response to a particular chemical or chemical group. A nanofiber sensor unit may combine a number of individual nanofiber sensors into an array, so that the combined responses form a response pattern or fingerprint unique to each chemical.

[0027] Using nanofiber sensors allows a continuous flow of particles to be analyzed, in contrast to having to collect finite samples for analysis, subjecting each sample to analysis and only then being able to further continue the analysis. Thus, a continuous flow of air is continuously, and without interruption, analyzed by the sensor, a manifold allowing adjusting the volume of air forwarded to the sensor.

[0028] In the present system, molecules to be analyzed are directed from a remote location and/or from multiple locations to a sensor using a ventilation unit.

[0029] The present system allows a constant flow of items, i.e. persons or parcels for example, to be processed for detection of target molecules, without interruption while being analyzed, thereby not requiring any item flow restriction or allowing only one item at a time, or at best restricting the flow of items to a single file.

[0030] The present system may be easily collapsible, transported and re-deployed at a new location. Due to its modular nature, the present system may be adapted to a range and size of doorways, entrance ways, throughways and enclosures or spaces.

[0031] The system allows for a covert installation since it may be integrated in existing ventilation system for example. [0032] The system is adaptable to static installations such as buildings, semi-permanent installations such as sea- containers serving as security check points, or mobile platforms such as vehicles. If incorporated into a semipermanent installation, the system may be designed to be easily movable and rapidly deployable in the desired location. The system is most likely to be placed at choke points, or at entrances of locations which are to be monitored and protected.

[0033] According to an aspect of the invention, there is provided a method using a close proximity nanofiber sensor for monitoring the presence of target molecules in an area. Air that may be containing the target molecules is collected from the area and directed to the sensor unit, which may be remotely located. Thus, instead of bringing the sensor close to the target molecules of interest, the molecules of interest are brought to the nanofiber sensor.

[0034] The method uses high volume flow ventilation, for generation of a high air flow allowing lifting any target molecules, such as explosive molecules, from their source and directing them through air ducts to the sensor for detection.

[0035] The air flow-rate through the detection sensor is monitored so as to match a limit to the volume of air or the speed of air that the sensor can effectively process, for example by: 1) using a manifold to direct a sample of air from the main air flow created by the ventilation unit, 2) selecting a sensor that allows higher volume or flow, 3) changing the flow velocity and pressure by varying ducts cross-section, 4) installing multiple sensors, 5) installing a turbulence generating device into the flow right before the sensor so as to further mix the air for example.

[0036] The sensitivity and selectivity of the sensor is selected so that the sensor is sensitive enough to detect a threat but not over sensitive so as to give false-positives, i.e. false alarms, and so that the sensor is selective enough to pick up the presence of target molecules even in presence of a range of other types of interfering molecules.

[0037] Target molecules may be explosives, narcotics and/or illicit substances for example.

[0038] Some molecules tend to attach to the walls of the ducts and air intakes of the system leading to the sensor unit , as is the case of a number of explosives that may be described as sticky; as result, such molecules may be stopped on their way to the sensor and thus fail to be detected. An anti-stick coating may be provided on the inner surface of the ducts to overcome this problem. Moreover, controlling the temperature and humidity in and around the ducts may be used to minimize molecular adhesion, so as to ensure that the target molecules reach the sensor without getting stuck on their way thereto.

[0039] Humidity and temperature are controlled so that they do not interfere with the reading of the sensor unit. If necessary, an air conditioning system may be integrated into the air ducts for temperature and humidity monitoring and control. A potential masking of the target chemical by the presence of other molecules in the air may be overcome by modifying the way the sensor itself functions, or by adding selective filters upstream of the sensor which will help to remove unwanted contaminants.

[0040] The present system and method comprises using an airflow control unit and a sensor unit, the airflow control unit directing target molecules from remote and/or multiple locations to the sensor unit for detection thereof, thereby allowing a flow of analytes, including for example persons, parcels, etc... to be analyzed without interference or interruption, even in a covert way as the system may be integrated in any regular ventilation system and therefore concealed from view. The present system and method may be adapted to fixed installations such as buildings, semi-permanent installations such as sea-containers serving as security check points as described hereinabove in relation to FIG. 3 for example, or mobile installation such as vehicle.

[0041] As people in the art may appreciate, units of the system as described herein may be organized in various configurations to achieve the detection goal. For example, the air pump or fan unit may be placed upstream or downstream of the sensor unit.

[0042] The scope of the claims should not be limited by the embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.