Sensor for measuring impedance of biological or chemical factor sample and method for detecting biological or chemical factor in sample using the sensor

Abstract

The subject of the invention is a sensor for impedance measurement of a sample of a biological or chemical factor in a potentiostat system, comprising a reference electrode RE and a counter electrode CE, wherein the electrical contacts lead to the edge of the sensor in the form of an edge connector, characterized in that the sensor comprises n working electrodes WEn, wherein n>2, preferably n is in the range of 2-256, and the reference electrode RE is common to all working electrodes WEn, and its segments presented by the working electrodes WEn form the measuring segments RE-CE-WEn. The subject of the invention is also a method for detecting chemical or biological factors in a sample using such a sensor.

Description

Technical Field

[0001] The subject of the invention is a sensor for impedance measurement of a sample of a biological or chemical agent in a potentiostat system, the sensor comprising a reference electrode (RE) and a counter electrode (CE), wherein electrical contacts lead to the edge of the sensor in the form of edge connectors. Background Art

[0002] In the prior art, there are many inventions that solve the problem of sensitive measurement of reagents in biological samples. Application US2014273549A1 proposes a solution, which relates to a multi-electrode single-channel biosensor in the form of a strip (for example, for measuring glucose in blood), which is connected to a measuring device using a slot. The strip includes many areas formed by conductors, and the edges of the strip are formed in a form suitable for the sensor slot and are equipped with many contacts. The device includes a measuring section, which includes several electrodes. Application WO2013114291A1 relates to a multi-channel temperature sensor in the form of a plate, wherein the formed track leads to an edge connector to connect to the slot of the sensing device. The plate includes many areas formed by conductors, and the edges are formed to be suitable for the sensor slot and the plate is equipped with many contact areas (edge ​​connectors). The measurements are performed simultaneously and in parallel. In the scheme, each measurement area is an independent measurement system, and the multi-channel characteristics are achieved by increasing the measurement system, and the number of circuit lines is also increased. Each of these measurement systems operates independently, so the sample measurement is not performed under the same conditions in each channel. Furthermore, such an electrode distribution increases the measurement time and does not provide the possibility of eliminating measurement errors.

[0003] Patent US6391558B1 proposes a nucleic acid detection system based on electrochemical methods. The system uses electrodes on the surface of a PCB, including an array of working electrodes and reference electrodes. The potential applied to the working electrode is composite, so that various ligands in a sample can be detected. The sensor electrode is connected to an analyzer, which detects signal changes caused by the interaction between the electrical pulse and the electrode.

[0004] Patent application US20030042150A1 describes an electrochemical sensor for detecting blood parameters such as glucose concentration, cholesterol level, etc. The system consists of a number of electrodes, which enable the simultaneous measurement of multiple parameters.

[0005] On the other hand, US6391558B1 describes a method for detecting nucleic acids using electrodes on a printed plate. The electrodes can be made of carbon or metals including copper, nickel, gold, platinum, palladium, etc. The printed plate is made using screen printing and then photolithography. The description does not cover the possibility of measuring simultaneously on multiple electrodes without multiplexing.

[0006] Biosensors based on electrochemical measurements are often used in point-of-care (PoC) devices. Ward et al. describe a method for determining P. aeruginosa using electrochemical impedance spectroscopy (EIS) in the publication PLOS ONE 2014 9 3 e91732 "Detecting P. aeruginosa with a Novel Biosensor". The measurement and result analysis are based on the change in impedance after the microorganism is connected to the biofilm on the electrode surface through pili, flagella or extracellular proteins, which leads to charge transfer, or by detecting metabolites produced by the microorganism.

[0007] International patent application WO2001083674A1 describes a method for detecting reagents using an electrochemical biosensor made of an electrode coated with a monolayer of biomolecules, preferably biotin and streptavidin selectively interacting. On the other hand, Moreira et al. (Sensors and Actuators B 223 (2016) 927-935) describe a sensor based on silver electrodes made using screen printing technology. The sensor includes artificial antibodies that recognize cancer biomarkers. Antibody detection signals are measured using a variety of methods such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (ESI), and square wave voltammetry (SWV).

[0008] A disadvantage of the inventions described in the prior art is the lack of the possibility of parallel multi-channel measurements of all measuring segments, which negatively affects the speed of measurement and its accuracy. In order to carry out multi-channel measurements using the solutions described in the prior art, a sensor system with signal multiplication is used, in which only one measuring segment is powered and registered during a given period, after which the system switches power and measurement to the next measuring segment. As a result, there is no possibility of simultaneous measurements. Each measuring segment has its own separate set of electrodes, and the resulting constant and random measurement errors detected on the reference electrode cannot be compensated in any way, since each reference electrode is an independent circuit (constant error for each electrode) and since the measuring segments are measured at different times, the random errors cannot be defined.

[0009] Surprisingly, it was found that the present invention solves this problem. Summary of the invention

[0010] The subject of the present invention is a sensor for impedance measurement of biological or chemical factor samples in a constant potential meter system, which includes a reference electrode RE and a counting electrode CE, wherein electrical contacts lead to the edge of the sensor in the form of edge connectors, preferably, the sensor comprises n working electrodes WEn, wherein n>2, preferably n is in the range of 2-256, and the reference electrode RE is common to all working electrodes WEn, and its segments presented by the working electrodes WEn form the measuring segment RE-CE-WEn.

[0011] Preferably, at least two and more preferably all WEn electrodes are coated on the outer surface with a layer of sensing material that reacts to only one type of biological or chemical agent in the sample.

[0012] Preferably, at least two WEn electrodes are coated with different sensing materials.

[0013] Preferably, the sensing material is of biological or synthetic type and in particular these are antibodies, antibody fragments, peptides, nucleic acid sequences for detecting biological or chemical factors in a sample.

[0014] Preferably, the shape of the working electrode Wen is the same circle and is positioned symmetrically relative to the counting electrode CE, wherein the edge of the counting electrode CE has the shape of a fragment of a circle concentric with these circles, wherein the reference electrode RE is located between the counting electrode CE and the working electrode WEn, and the shape of the reference electrode RE is the same as the outline of the counting electrode CE.

[0015] Preferably, the sensor comprises additional connected and / or non-connected electrodes to encode the number of the working electrodes WEn, wherein n>2, preferably, n is in the range of 2-256.

[0016] Preferably, the arrangement of the working electrode WEn, the counter electrode CE and the reference electrode RE constitutes a measurement segment with the same shape and repeating, and the distance between the working electrode WEn, the counter electrode CE and the reference electrode RE is the same in each measurement segment, and furthermore, the area of ​​the working electrode WEn, the counter electrode CE segment and the reference electrode RE segment is the same in each segment. The shape of the reference electrode RE includes the distribution of the electric field gradient in the polarization sensor, substantially reflecting the same potential value in the polarization electrolyte.

[0017] Preferably, the arrangement and shape of the working electrode WEn, the reference electrode RE and the counter electrode CE have their symmetry axes.

[0018] Preferably, the edge connector has a contact field which forms an electrical circuit independent of the WEn electrode, the reference electrode RE and the counter electrode CE for identifying the correct positioning of the sensor in the slot of the measuring system by connecting measuring slot contacts during insertion of the sensor into the slot.

[0019] Preferably, the sensor comprises 9 contact points for encoding the sensor number.

[0020] Preferably, the edge connector is an HDMI plug (High Definition Multimedia Interface) or a DisplayPort plug (Universal Digital Interface).

[0021] The subject of the present invention is a method for detecting biological or chemical factors in a sample, characterized in that a sample of the biological or chemical factor in the form of an electrolyte or solution is placed in a device according to any one of the preceding claims 1 to 11, so that all working electrodes WEn, counting electrodes CE and reference electrodes RE are covered with the sample in the form of a solution, and then 2-256 sample measurements are performed simultaneously, in particular using impedance spectroscopy or voltammetry, and the presence of the biological or chemical factor in the sample is determined based on the results of these measurements.

[0022] Preferably, the measurement is performed in an inverse configuration, wherein the reference electrode RE serves as the counting electrode CE and the counting electrode CE serves as the reference electrode RE.

[0023] Preferably, the measurement is performed in an opposite configuration, wherein the excitation signal is applied to the WEn electrode instead of the CE electrode. Compared to the standard configuration, the electrode configuration reversal enables various resulting characteristics of the electrode impedance to be obtained. The differences presented are the result of the nonlinearity of the effect that occurs in the sensor-biosensitive layer-test sample system. Here, the possibility of reversing the electrode polarization (thereby reversing the direction of charge movement, including ions in the solution) and the change of the measurement system configuration (measurement method of the current of each electrode) are critical. In particular, in this way, the nonlinearity of the impedance characteristics can be measured, which is caused by the presence of a pn junction in the measured system.

[0024] Preferably, the biological or chemical agent is a pathogen, in particular a virus, a bacterium, a fungus, proteins and fragments thereof, including enzymes, antibodies, structural proteins, antibody fragments, peptides, affibodies, nucleic acids and nucleotide sequences, including single-stranded and double-stranded DNA, RNA, aptamers, short nucleotide sequences, fatty acids, carbohydrates, glycolipids, glycopeptides and other organic compounds, such as pesticides, antibiotics, non-organic compounds, including heavy metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be explained in more detail by means of preferred embodiments with reference to the accompanying drawings, in which:

[0026] Figure 1 A sensor 1 for impedance measurement in a potentiostat system is shown, comprising a reference electrode RE 3 and a counter electrode CE 4, wherein an electrical contact 5 in the form of an edge connector leads to an edge 6 of the sensor 1. The proposed sensor 1 is equipped with working electrodes WEn 7, wherein n=8, and the reference electrode RE 3 is common to all working electrodes WEn 7 and its segment located near the working electrode WEn 7 forms a sensing segment 8 of RE-CE-WEn type.

[0027] Figure 2 The edge 6 of the sensor 1 is shown in the form of an edge connector, wherein the contact points 11 form a circuit separate from the electrodes WEn7, RE3 and CE 4, intended to identify the correct placement of the sensor in the measuring tank, and further connected and / or non-connected electrodes 13 for encoding the number of the working electrode Wen 7.

[0028] Figure 3 The schematic diagram of the identification system of a sensor coded as "11001" is shown. The number of possible combinations is 32 (2^M for M=4).

[0029] Figure 4 A schematic diagram of a simplified version of the system is shown, a subset of 3 electrical contacts 5 is used for identification, so the number of combinations is 2^M=8.

[0030] Figure 5 Shown are the measurement results of the sensor interaction with a positive sample (lactose product).

[0031] Figure 6 Shown are the measurement results of the sensor interaction with a negative sample (lactose-free product).

[0032] Figure 7 Shown is the interaction of the ssDNA modified sensor with a complementary sequence.

[0033] Figure 8 Shown are the results of electrochemical impedance spectroscopy measurements on a copper electrode covered with a biolayer that was treated successively with: 0.5 M NaCl, artificial saliva with Triton X buffer (1%), H1N1 virus in Triton X buffer with 0.5 M NaCl additive.

[0034] Fig. 9 are top and cross-sectional views of a sensor 1 covered with a sensing material 9 (biolayer), and an applied sample 2 of a biological or synthetic agent. DETAILED DESCRIPTION

[0035] In a preferred embodiment, the working electrode WEn 7 is coated with a sensing material 9, thus being a substance responsible for detecting specific biological and chemical substances and particles in the sample 2, preferably in the form of a solution or suspension.

[0036] The working electrode RE 3 and the counting electrode CE 4 are auxiliary electrodes shared by all electrodes WEn 7 during measurement and are used to measure the change in charge due to the chemical process occurring in the sensing material 9 placed on the electrode WEn7, the above chemical process is caused by the biological or chemical factors used for detection in the sample 2.

[0037] The sensor edge connector 1 is mechanically and partially electrically compatible with a standard HDMI port or DisplayPort. In typical use, HDMI and DisplayPort type ports are used to transmit digital data and contain two rows of contacts in the housing that maintain the electrical connection between the port and the inserted plug. The mechanical structure of the HDMI / DP port and the plug prevents them from being connected in reverse.

[0038] However, in the proposed solution, the sensor 1 is not equipped with an HDMI / DP port, nor any mechanical element providing similar functionality to prevent the sensor from being inserted into the sensor slot in reverse. Therefore, without any additional mechanical protection, it is possible that the sensor 1 is inserted into the measurement slot in reverse, which prevents the measurement. In this case, another problem is that the structure of the standard HDMI / DP port-contacts is placed in an alternating manner rather than in an opposite manner, which makes it virtually impossible to use the electrical contacts 5 on the edge 6 of the edge connector to unambiguously detect that the sensor 1 is inserted in reverse into the sensor slot. This is due to the fact that if inserted in reverse, the connection point of the sensor slot and the center of the electrical contact 5 do not overlap, and the connection point moves to the isolated area between the electrical contacts 5. As a result, it is possible to obtain a short circuit of adjacent electrical contacts 5 through the slot contact, as well as an electrical connection with any of these electrical contacts 5. This phenomenon is actually unpredictable, and the result obtained may be completely different from the next attempt to insert the sensor 1 into the sensor slot in the opposite direction. This is due to the mismatch of the gap between the socket housing and the edge connector and the deviation of the edge 6 of the edge connector from the direction at right angles to the symmetry axis of the socket.

[0039] Surprisingly, it was found that it is possible, even if this cannot be excluded, to detect the correct or incorrect orientation of the sensor 1 when it is inserted into the sensor slot based solely on electrical measurements. It is necessary to design the connection point 11 in such a way that the portion of the edge connector closer to the edge 6 of the sensor 1 is used as the connection point 11 for detecting the orientation of the sensor in the socket, while other areas of the edge connector maintain electrical contact between the socket connection and the electrical contacts 5 that are connected to the respective sensor electrodes. This embodiment is Figure 2 During the insertion of the sensor 1 into the socket, a temporary connection of the contacts 1-2-3-4 and 6-7-8-9 of the connection socket occurs through the connection point without a connection to the contact 5. The method of the invention for detecting the orientation of the sensor 1 relative to the slot is entirely based on electrical measurements made by monitoring the short circuits between the sets of electrical connectors during the insertion of the sensor 1 into the sensor socket and does not functionally limit or affect the operation of the sensor 1 after full insertion.

[0040] Variants of the described solution cover the isolation of the connection points 11 of the upper side, the lower side or both the upper side and the lower side of the edge connector in various configurations of the circuit connection of the sensor slot.

[0041] Only after the correct orientation of the sensor 1 in the sensor slot is detected, the electrical signals required for identification of the sensor 1 and correct measurement are activated.

[0042] Example 1

[0043] Identification of sensor type

[0044] The versatility of the sensor includes its use for detecting various biological or chemical substances. The sensor 1 can be made in a variety of versions, which differ in the type of sensing material of the working electrode WEn 7 that is sensitive to a particular selected pathogen or other substance. Therefore, it is necessary to enable the clear identification of the type of sensor 1 located in the sensor and to select measurement conditions that vary according to the type of sensor 1, such as the excitation signal value and the measurement time, based on this. Common solutions are based on colorimetric recognition, the use of codes based on optical image analysis (e.g., barcodes, QR codes) or dedicated electronic systems for wired or wireless identification (e.g., RFID).

[0045] The same electrical contacts 5 used for measuring the working electrode WEn 7 can be used to identify the type of sensor 1. The encoding of the sensor 1 type is performed by selecting a subset of N electrical contacts 5 from the available M electrical contacts 5, where N < M. The selected combination of N electrical contacts 5 is also connected to the reference electrode RE 3 or the counter electrode CE 4 or the shielding electrode GE 14. The sensor circuit detects which electrical contacts 5 are connected, and the electrical contacts 5 connected in this way are not used in the further steps of the appropriate measurement.

[0046] according to Figure 3 , the electric contacts 1, 2 and 5 leading to the working electrodes WE1 and WE2 7 are not electrically connected to any of the wires of the electric contacts 5 of the electrodes CE 4, RE3 and GE 14, so these electrodes are used to measure the content of biological or chemical factors. The electric contacts 5 of No. 3 and No. 4 are connected to the electrode GE 14 located in the center. The initial voltage polarization VPOL of all the electric contacts 5 relative to GE14 or RE, CE in the range of 500mV to 5V gives a measurement result similar to VGE of only the electric contacts 5, 3 and 4, and the voltage measurement result is similar to VPOL of the electric contacts 5 of No. 1, 2 and 5. The code "11001" is obtained when the symbol "0" is assigned to the potential similar to VGE and the symbol "1" is assigned to the potential similar to VPOL.

[0047] The proposed solution is able to encode 2^N various combinations in which a selected subset of the electrical contacts 5 of the edge connector arranged in any combination is connected or not connected to the electrode GE14, the electrode RE3 or the counting electrode CE4. For this exemplary solution, the subset of electrical contacts 5 identified with N=3 electrical contacts 5 is able to unambiguously identify 8 different types of sensors 1. Similarly, for N=8, 256 types of sensors 1 can be identified.

[0048] This solution can utilize all electrical contacts 5 for identifying the type of sensor 1, providing a higher number of combinations, namely 32 combinations (2^M for M=4).

[0049] Figure 4 It is a simplified version of the layout diagram, in which the subset includes 3 electrical contacts 5, so the number of combinations is 2^M=8.

[0050] Sensor Operation

[0051] In the case of the proposed solution, each individual measurement segment 8 consisting of the working electrode WEn 7 and the corresponding segments of the reference electrode RE 3 and the counter electrode CE 4 is identical, i.e. the distance between these elements remains the same and the area values ​​remain constant. The potential of the reference electrode RE 3 is constant throughout the system, providing ideal measurement conditions for the entire system. All other electrode pairs work in the same way and the reference electrode RE 3 equalizes the potential around the other electrodes.

[0052] The working electrode WEn 7, the reference electrode RE3, and the counter electrode CE4 are made of a low resistivity material, such as copper, whose resistivity is negligible compared to the resistivity of the sample 2 or the sensing material 9 that reacts with specific chemical and biological substances, such as the pathogen being detected.

[0053] The multichannel system showed a negative influence of the potential gradient on the results obtained from each channel.

[0054] In the proposed multi-channel sensor 1 solution, the measuring sensor 8 is used to form a system of working electrodes WEn 7, working electrodes 3 and counting electrodes 4, so that each measuring segment 8 maintains the same geometric shape, in particular, the areas of the individual electrodes are the same, and the distance between the electrodes and the shape of the electrodes are distributed so that the path of the RE electrode corresponds to a certain fixed potential in the electric field line distribution in the polarization sensor 1.

[0055] Surprisingly, during the tests carried out, it was found that an electrode system designed in this way provides very good reproducibility of results independently of the WEn electrode 7 analyzed and also enables the use of the novel impedance measurement method.

[0056] N1 measurement method

[0057] Compared to classical impedance spectroscopy using a potentiostat system, the purpose of the reference electrode RE 7 is to measure the potential in the sample 2 solution in the form of an electrolyte in order to compensate (eliminate) the electrolyte impedance from the final result, which is the impedance value within the CE-WEn electrode system rather than reaching a set potential due to the change in the potential of the counter electrode CE 4.

[0058] N2 Method

[0059] Compared to the classical measurement method used in impedance spectroscopy using a potentiostat, the roles of the working electrode WEn 7 and the counter electrode CE 4 are changed, and in this system the excitation is generated by the working electrode WEn 7 rather than by the counter electrode CE 4. Similar to method N1, the role of the working electrode RE7 is to measure the potential distribution in the electrolyte. Unexpectedly, it was found that the impedance values ​​measured using method N2 were different from the values ​​obtained using the conventional method or the N1 method, and that cyclically switching the operating mode of the measurement system between N1 and N2 can provide further information about the measured sample.

[0060] The N1 and N2 methods are characterized in that there are typically no restrictions on impedance measurements usually performed with a potentiostat system, and in particular, the measurements of all working electrodes WEn 7 can be performed simultaneously.

[0061] The results show that, in addition to the beneficial increase in the amount of data obtained on a given sample 2 while changing the N1 and N2 methods, another advantage is that the measurement time is significantly reduced compared to the measurement with time multiplexing, based on the separate measurements for each electrode. The gain in reducing the measurement time using the N1 and N2 methods is directly proportional to the number of channels and, for 8 channels measured simultaneously, is 8 times shorter than a similar measurement using the traditional method (i.e. time multiplexing).

[0062] Unlike in conventional electrochemical measurements, the electrolyte is only a wetting aid for conductivity and the electrode geometry eliminates the influence of the electrolyte itself on the impedance.

[0063] The construction and mutual arrangement of the electrodes also enable the use of a reverse detection mode. In a classical system, the excitation occurs at the counter electrode CE 4 and the signal is recorded with the working electrode WEn 7. In the case of this given solution, the measurement can be performed in such a way that the excitation at the working electrode WEn 7 and the counter electrode CE 4 serves as a reference for the entire measurement system. The reversal of the direction of the ionic current through the electrolyte produces results that differ in certain frequency ranges from those obtained using conventional methods, which improves the device sensitivity and increases its ability for automatic fault detection of the sensor 1 or of individual electrodes.

[0064] Example 2

[0065] Analysis of lactose-electrode interaction

[0066] The surface of the working electrode WEn 7 was modified with β-galactosidase. Subsequently, the working electrode WEn 7 (prepared for working, therefore wetted with the zeroing solution for electrode activation) was zeroed with buffer and then the sample 2 was applied as a lactose-containing solution. Figure 5 A clear change in impedance is shown in the presence of lactose.

[0067] Samples without lactose were used as control experiments. Figure 6 As shown, during the presence of the control sample, sensor 1 exhibited no change.

[0068] Example 3

[0069] Analysis of DNA interactions on electrodes

[0070] Before the measurement, working electrodes WEn 7 of No. 1 to No. 8 were cleaned with H2SO4. First, the measurement was performed with the clean working electrode WEn7, and then the sensing material 9 was prepared thereon. The sensing material 9 was prepared in the following manner:

[0071] Deposit modified SH-DNA forms (ssDNA) and incubate at room temperature for 2-24 hours.

[0072] • Subsequently, 10 μl of MCH solution (complementary DNA, CssDNA) was applied and washed with PBS buffer, pH 7.4 to remove free molecules.

[0073] The sensor 1 prepared in this way with the sensing material 9 enables, for example, measurements to be made using electrochemical impedance spectroscopy, which shows the interaction of the modified SH-DNA (attached to the electrode surface) with the complementary DNA present in the sample being measured.

[0074] The results are shown in Figure ( Figure 7 ) shows that the increase in impedance is caused by the interaction between complementary DNA and the modified DNA.

[0075] Example 4

[0076] Analysis of the copper surface sensor interaction - virus H1N1 560:

[0077] Modification of the sensor surface with a biolayer (with anti-MI antibodies)

[0078] so-called "zeroing" of the sensor modified with the antibody - the first step to correctly measure the bioactivity of the sensor, thereby preparing the dried peptide layer for testing,

[0079] Analyze the interaction between the sensor and a negative sample in the form of artificial saliva supplemented with 1% Triton X

[0080] Analyze the interaction between the sensor and samples containing the H1N1 virus

[0081] The results are Figure 8 Shown in.

[0082] Results: Sensor modified with antibodies on copper substrate:

[0083] Shows a slight change in impedance during interaction with the negative sample, artificial saliva supplemented with 1% Triton X;

[0084] • It shows that during the interaction of the peptide with the virus-containing sample, the impedance changes (increases) significantly.

Claims

1. A sensor for measuring the impedance of a biological or chemical factor sample in a potentiostat system, the sensor comprising a reference electrode RE (3) and a counter electrode CE (4), electrical contacts in the form of edge connectors leading to the edge of the sensor, characterized in that: The sensor comprises n working electrodes WEn (7), wherein n is in the range of 2-256, and the reference electrode RE (3) is common to all the working electrodes WEn (7), and the fragments thereof presented by the working electrode WEn (7) form a measurement segment (8) RE-CE-Wen, the arrangement of the working electrode WEn (7), the counting electrode CE (4) and the reference electrode RE (3) constitutes a measurement segment (8) of the same shape and repetitive, and the distances between the working electrode WEn (7), the counting electrode CE (4) and the reference electrode RE (3) are the same in each measurement segment (8), and the areas of the working electrode WEn (7), the fragments of the counting electrode CE (4) and the fragments of the reference electrode RE (3) are the same in each segment; The working electrode WEn (7) is shaped into the same circle and is positioned symmetrically relative to the counting electrode CE (4), wherein the edge of the counting electrode CE (4) is shaped as a circle concentric with these circles, the reference electrode RE (3) is located between the counting electrode CE (4) and the working electrode WEn (7), and the shape of the reference electrode RE (3) is the same as the outline of the counting electrode CE (4).

2. The sensor according to claim 1, characterized in that At least two working electrodes WEn (7) are coated with a sensing material (9) layer on the outer surface, and the material of the sensing material (9) layer only reacts with one type of biological or chemical factor in the sample (2).

3. The sensor according to claim 2, characterized in that At least two of the working electrodes WEn (7) are coated with different sensing materials (9).

4. The sensor according to claim 2, characterized in that The sensing material (9) is a biological or synthetic type of material and is a selective antibody, antibody fragment, peptide, nucleic acid sequence for detecting biological or chemical factors in the sample (2).

5. The sensor according to claim 1, characterized in that The sensor comprises additional connected and / or non-connected electrodes (13) to encode the number of the working electrode WEn (7), where n is in the range of 2-256.

6. The sensor according to claim 1, characterized in that The arrangement and shape of the working electrode WEn (7), the reference electrode RE (3) and the counter electrode CE (4) have a symmetry axis.

7. The sensor according to claim 1, characterized in that The edge connector has contact points (11), which constitute a circuit independent of the working electrode WEn (7), the reference electrode RE (3) and the counting electrode CE (4) and are used to identify the correct positioning of the sensor (1) in the slot by connecting the measurement slot contacts when the sensor (1) is placed in the slot of the measuring system.

8. The sensor according to claim 7, characterized in that The edge connector is an HDMI port, ie High Definition Multimedia Interface, or a DisplayPort, ie Universal Digital Interface.

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