Sensor, a sensor array, and a method of operating a sensor

Abstract

In an example embodiment, there is a sensor for detecting particles. The sensor comprises an electrode, a sensor active region covering the electrode and the sensor active region is sensitive-for the particles. A first switch element is operable to bring the electrode to a first electric potential when the first switch element is closed, and a second switch element is operable to bring the electrode to a second electric potential when the second switch element is closed. A detector is adapted to detect the particles based on a change of the electric properties of the sensor in an operation mode in which the electrode is brought to the first electric potential and an operation mode in which the electrode is brought to the second electric potential.

1 . A sensor for detecting particles, the sensor comprising
 an electrode;   a sensor active region covering the electrode and being sensitive for the particles;   a first switch element operable to bring the electrode to a first electric potential when the first switch element is closed;   a second switch element operable to bring the electrode to a second electric potential when the second switch element is closed;   a detector adapted to detect the particles based on a change of the electric properties of the sensor in an operation mode in which the electrode is brought to the first electric potential and an operation mode in which the electrode is brought to the second electric potential.   
     
     
         2 . The sensor of  claim 1 ,
 wherein the electrode is a sub-micron electrode, particularly a nanoelectrode.   
     
     
         3 . The sensor of  claim 1 ,
 wherein the first switch element and the second switch element are transistors,   wherein the electrode is coupled to a first source/drain region of a transistor forming the first switch element and is coupled to a first source/drain region of a transistor forming the second switch element;   wherein the first electric potential is coupled to a second source/drain region of the transistor forming the first switch element;   wherein the second electric potential is coupled to a second source/drain region of the transistor forming the second switch element.   
     
     
         4 . The sensor of  claim 1 ,
 wherein the sensor active region comprises at least one capture probe adapted for hybridizing with the particles.   
     
     
         5 . The sensor of  claim 4 ,
 comprising a self assembled monolayer between the electrode and the at least one capture probe.   
     
     
         6 . The sensor of  claim 1 ,
 comprising a clock adapted for providing the first switch element and the second switch element with clock signals to operate the first switch element and the second switch element to alternate between an operation mode in which the first switch element is closed and the second switch element is simultaneously open and an operation mode in which the first switch element is open and the second switch element is simultaneously closed.   
     
     
         7 . The sensor of  claim 1 ,
 wherein the detector is adapted to detect the particles based on a net charge transferred between a node providing the first electric potential and a node providing the second electric potential during one or more cycles in which, in an alternating sequence, the electrode is brought to the first electric potential and in which the electrode is brought to the second electric potential.   
     
     
         8 . The sensor of  claim 1 ,
 wherein the detector is adapted to detect the particles based on a change of a capacitance in an operation mode in which the electrode is brought to the first electric potential and an operation mode in which the electrode is brought to the second electric potential.   
     
     
         9 . The sensor of  claim 1 ,
 comprising a further electrode configured to be kept at a fixed third electric potential.   
     
     
         10 . The sensor of  claim 1 , manufactured in CMOS technology. 
     
     
         11 . The sensor of  claim 1 ,
 adapted as a biosensor, particularly adapted as one of the group consisting of a single-molecule biosensor, a capacitive biosensor, or an electrochemical biosensor.   
     
     
         12 . A sensor array, comprising an arrangement of a plurality of sensors of  claim 1 . 
     
     
         13 . The sensor array of  claim 12 ,
 wherein the plurality of sensors are arranged in rows and columns, wherein the first electric potential is provided in common for at least two, particularly for all sensors of a column and the second electric potential is provided in common for at least two, particularly for all sensors of a row.   
     
     
         14 . The sensor array of  claim 13 ,
 wherein clock signals of a clock are provided in common for at least two, particularly for all sensors of a row.   
     
     
         15 . The sensor array of  claim 13 ,
 wherein sensors in adjacent rows are arranged upside down to one another to share one of the group consisting of the first electric potential and the second electric potential.   
     
     
         16 . The sensor array of  claim 13 ,
 wherein sensors in adjacent columns are arranged flipped left/right to one another to share one of the group consisting of the first electric potential and the second electric potential.   
     
     
         17 . The sensor array of  claim 12 ,
 monolithically integrated in a common substrate.   
     
     
         18 . The sensor array of  claim 17 ,
 wherein the first switch element, the second switch element and the detector of the plurality of sensors are arranged within the substrate;   wherein the electrode and the sensor active region of the plurality of sensors are provided at a surface of the substrate;   the sensor array further comprising a moisture resistant structure at the surface of the substrate between adjacent ones of the electrodes of the plurality of sensors.   
     
     
         19 . The sensor array of  claim 13 ,
 comprising a selection unit adapted for selecting one of the rows for sensing, wherein the selection unit is further adapted for disabling all other rows from sensing by opening the first switch element and the second switch element of the all other rows.   
     
     
         20 . The sensor array of  claim 13 ,
 comprising a selection unit adapted for selecting one of the rows for sensing, wherein the selection unit is further adapted for disabling all other rows from sensing and for closing the first switch element or the second switch element of at least a part of the all other rows to thereby provide one of the group consisting of a counter electrode functionality and a reference electrode functionality.   
     
     
         21 . The sensor array of  claim 13 ,
 comprising a row periphery circuit comprising a number of multiplexers adapted for gating the rows.   
     
     
         22 . The sensor array of  claim 21 ,
 wherein the row periphery circuit comprises five multiplexers for each pair of rows, the five multiplexers being configured to provide clock signals (ΦT, ΦD) to operate the first switch element and the second switch element and to provide the first electric potential or the second electric potential to the sensors of a respective pair of rows.   
     
     
         23 . The sensor array of  claim 13 ,
 comprising a column periphery circuit adapted for gating the columns.   
     
     
         24 . The sensor array of  claim 13 ,
 comprising a calibration row having one or more calibration units each of which being constituted as each of the plurality of sensors but being free of an electrode and of a sensor active region.   
     
     
         25 . The sensor array of  claim 12 ,
 wherein the detector of at least a part of the plurality of sensors is adapted to perform a self-referencing function by comparing a detection signal with an average detection signal of at least a part of the other sensors, particularly by comparing the detection signal with an average detection signal of other sensors of a row.   
     
     
         26 . The sensor array of  claim 12 ,
 wherein the detector is adapted to detect the particles in an operation mode in which the electrode is statically brought to the first electric potential and is statically decoupled from the second electric potential.   
     
     
         27 . The sensor array of  claim 13 ,
 wherein active regions and polysilicon lines of the sensor array are formed by orthogonal continuous stripes with contact holes to source/drain parts of the active regions between every pair of adjacent polysilicon lines.   
     
     
         28 . The sensor array of  claim 13 ,
 wherein a detector for measuring transferred charge comprises a source follower transistor to control the first electric potential on the columns, an integration capacitor provided by a gate capacitance of a further transistor that also serves as a read out transistor, a reset transistor, and a selection transistor connected to a read line being part of a read bus.   
     
     
         29 . The sensor array of  claim 13 ,
 wherein a detector for measuring transferred charge comprises a source follower, a reset transistor, a separate integration capacitor, and transistors of opposite conduction type so that one of these transistors is operable as a source follower to measure a voltage on the integration capacitor.   
     
     
         30 . The sensor array of  claim 13 ,
 comprising at least one on-chip digital circuit to accumulate or average consecutive measurements performed on the same sensors, particularly performed by sensors of a row, to thereby improve the signal to noise ratio.   
     
     
         31 . A method of detecting particles using a sensor, the method comprising
 bringing a sensor active region covering an electrode in contact with the particles;   bringing the electrode to a first electric potential;   subsequently bringing the electrode to a second electric potential;   detecting the particles based on a change of the electric properties of the sensor, particularly of the electrode, in an operation mode in which the electrode is brought to the first electric potential and an operation mode in which the electrode is brought to the second electric potential.   
     
     
         32 . The method of  claim 31 ,
 comprising operating the sensor so that double sampling is used to reduce an effect of a low frequency noise of a read out transistor.