Electrochemical imaging method, electrochemical measurement apparatus and transducer

Abstract

In an electrochemical imaging method of, by applying voltages between working electrodes arranged in a measurement area and a counter electrode and causing the working electrodes to perform a redox reaction by giving and reception of electrons to and from a plurality of measurement target substances generated or consumed by a sample in an electrolytic solution to measure currents that flow through the individual electrodes, imaging images of density distributions of the measurement target substances based on distributions of the currents in the measurement area, the working electrodes are arranged in the measurement area in a manner of being arranged uniformly in each of a plurality of working electrode groups, each of the working electrode groups comprising a plurality of working electrodes, and in a manner of being mutually mixed; applied voltages specified for the working electrode groups, respectively, are simultaneously applied between the working electrodes and the counter electrode; any two working electrode groups among the plurality of working electrode groups are mutually different in at least any of the determined voltage, presence/absence of a molecular modification of an electrode surface and a species of the molecular modification; and based on the individual distributions of the currents in the measurement area in the working electrode groups, the images of density distributions of the measurement target substances are acquired by simultaneous measurements.

What is claimed is: 
     
         1 . An electrochemical imaging method for generating a plurality of images of density distributions of a plurality of measurement target substances which are generated or consumed by a sample in an electrolytic solution, comprising the steps of:
 (a) providing a plurality of working electrodes arranged in a measurement area that faces the electrolytic solution, and a counter electrode placed in the electrolytic solution, wherein
 the plurality of working electrodes comprises a plurality of working electrode groups each of which includes a plurality of working electrodes, the plurality of working electrodes included by each one of the plurality of working electrode groups, respectively, being arranged uniformly in the measurement area, such that the working electrodes included by all of the plurality of working electrode groups are mutually mixed in the measurement area; 
   (b) applying a voltage between each of the working electrodes included by all of the plurality of working electrode groups and the counter electrode, all simultaneously, and causing thereby the working electrode to perform a redox reaction that is one of giving electrons to and receiving electrons from one of the plurality of measurement target substances, wherein
 the voltage is determined in accordance with the working electrode group that includes the working electrode; 
   (c) measuring a current that flows through each of the working electrodes included by all of the plurality of working electrode groups; and   (d) generating an image of a density distribution in the measurement area of each of the plurality of measurement target substances based on a distribution in the measurement area of the measured currents that flow through the working electrodes included by one of the plurality of working electrode groups that corresponds to the measurement target substance;
 wherein any two working electrode groups among the plurality of working electrode groups are mutually different in at least any of the determined voltage, presence/absence of a molecular modification of an electrode surface and a species of the molecular modification; and wherein 
 based on the individual distributions of the currents in the measurement area in accordance with the working electrode groups, the plurality of images of density distributions of the plurality of measurement target substances are acquired by simultaneous measurements. 
   
     
     
         2 . The electrochemical imaging method according to  claim 1 , wherein step (d) further comprises data processing for interpolating the distribution of the measured currents at a position where any of the working electrodes included by the one of the plurality of working electrode groups does not exist. 
     
     
         3 . The electrochemical imaging method according to  claim 1 , further comprising the step of:
 displaying two or more of the images of density distributions generated in step (d) in an overlapped manner on a display portion.   
     
     
         4 . The electrochemical imaging method according to  claim 3 , wherein, on the display portion, the two or more of the images of density distributions are differentiated by colors, and the colors are additively mixed and displayed on an overlap of the images. 
     
     
         5 . An electrochemical imaging method for generating a plurality of images of density distributions of a plurality of measurement target substances which are generated or consumed by a sample in an electrolytic solution, comprising the steps of:
 (a) providing a plurality of working electrodes arranged in a measurement area that faces the electrolytic solution, and a counter electrode and a reference electrode both placed in the electrolytic solution, wherein
 the plurality of working electrodes comprises a plurality of current measurement working electrodes and a plurality of potential measurement working electrodes, the plurality of current measurement working electrodes and the plurality of potential measurement working electrodes, respectively, being arranged uniformly in the measurement area, such that the current measurement working electrodes and the potential measurement working electrodes are mutually mixed in the measurement area; 
   (b) applying a voltage between each of the plurality of current measurement working electrodes and the counter electrode all simultaneously, and causing thereby the current measurement working electrode to perform a redox reaction that is one of giving electrons to and receiving electrons from a first substance, the first substance being one of the plurality of measurement target substances;   (c) measuring a current that flows through each of the plurality of current measurement working electrodes;   (d) at the same time as step (c), measuring a potential of each of the plurality of potential measurement working electrodes that is influenced by a second substance, with the reference electrode as a reference, the second substance being another one of the plurality of measurement target substances; and   (e) generating both of an image of a density distribution in the measurement area of the first substance based on a distribution in the measurement area of the measured currents and an image of a density distribution in the measurement area of the second substance based on a distribution in the measurement area of the measured potentials.   
     
     
         6 . The electrochemical imaging method according to  claim 5 , wherein
 the first substance further comprises a plurality of first measurement target substances;   the plurality of current measurement working electrodes further comprises a plurality of current measurement working electrode groups each of which includes a plurality of current measurement working electrodes, the plurality of current measurement working electrodes included by each one of the plurality of current measurement working electrode groups, respectively, being arranged uniformly in the measurement area, such that the working electrodes included by all of the plurality of current measurement working electrode groups are mutually mixed in the measurement area;   the voltages is determined in accordance with the current measurement working electrode group that includes the current measurement working electrode;   generating further an image of a density distribution in the measurement area of each of the plurality of first measurement target substances based on a distribution in the measurement area of the measured currents that flow through the current measurement working electrodes included by one of the plurality of current measurement working electrode groups that corresponds to the first measurement target substance;   any two current measurement working electrode groups among the plurality of current measurement working electrode groups are mutually different in at least any of the determined voltage, presence/absence of a molecular modification of an electrode surface and a species of the molecular modification; and   based on the individual distributions of the currents in the measurement area in accordance with the current measurement working electrode groups, the plurality of images of density distributions of the plurality of first measurement target substances are acquired.   
     
     
         7 . The electrochemical imaging method according to  claim 5 , wherein step (e) further comprises data processing for interpolating at least one of the distribution of the measured currents at a position where any of the current measurement working electrodes corresponding to the distribution of the measured currents does not exist, and the distribution of the measured potentials at a position where any of the potential measurement working electrodes does not exist. 
     
     
         8 . The electrochemical imaging method according to  claim 5 , further comprising the step of:
 displaying two or more of the images of density distributions generated in step (e) in an overlapped manner on a display portion.   
     
     
         9 . The electrochemical imaging method according to  claim 8 , wherein, on the display portion, the two or more of the images of density distributions are differentiated by colors, and the colors are additively mixed and displayed on an overlap of the images. 
     
     
         10 . An electrochemical measurement apparatus, comprising:
 an electrolytic solution tank capable of containing an electrolytic solution and a sample that generates or consumes a plurality of measurement target substances in the electrolytic solution;   a plurality of working electrodes arranged in a measurement area, the measurement area being provided on a bottom surface of the electrolytic solution tank, wherein   the plurality of working electrodes comprises a plurality of working electrode groups each of which includes a plurality of working electrodes, the plurality of working electrodes included by each one of the plurality of working electrode groups, respectively, being arranged uniformly in the measurement area, such that the working electrodes included by all of the plurality of working electrode groups are mutually mixed in the measurement area;   a counter electrode provided in the electrolytic solution tank;   a voltage applying portion having a function of applying a voltage between each of the working electrodes included by all of the plurality of working electrode groups and the counter electrode, all simultaneously, wherein   the voltage is determined in accordance with the working electrode group that includes the working electrode; and   a current measuring portion configured to measure a current that flows between each of the working electrodes included by all of the plurality of working electrode groups and the counter electrode;   wherein any two working electrode groups among the plurality of working electrode groups are mutually different in at least any of the determined voltage, presence/absence of a molecular modification of an electrode surface and a species of the molecular modification; and whereby   a distribution in the measurement area of the currents that flow through the working electrodes included by each one of the plurality of working electrode groups is acquired.   
     
     
         11 . The electrochemical measurement apparatus according to  claim 10 , wherein the working electrode included by each of the plurality of working electrode groups has an electrode area which is determined in accordance with the working electrode group that includes the working electrode, and at least two of the working electrode groups have mutually different electrode areas. 
     
     
         12 . The electrochemical measurement apparatus according to  claim 10 , wherein at least two of the plurality of working electrode groups are mutually different in density as number of the working electrodes per unit area of the measurement area. 
     
     
         13 . The electrochemical measurement apparatus according to  claim 10 , wherein a plurality of configuration units are cyclically arranged on the measurement area, the configuration unit being defined as a determined closed plane figure having therein arranged a determined set of working electrodes, the determined set of working electrodes comprising all of a respectively determined number of the working electrode(s) included by each of the plurality of working electrode groups, wherein the respectively determined number is a positive natural number determined in accordance respectively with each of the plurality of the working electrode groups. 
     
     
         14 . The electrochemical measurement apparatus according to  claim 13 , wherein all the configuration units have a same arrangement pattern of the set of working electrodes in the configuration unit. 
     
     
         15 . The electrochemical measurement apparatus according to  claim 10 , further comprising a data processing portion configured to interpolate the acquired distribution of the currents at a position where any of the working electrodes included by the one of the plurality of working electrode groups does not exist. 
     
     
         16 . The electrochemical measurement apparatus according to  claim 10 , further comprising a display portion configured to overlappingly display two or more of images of the acquired distributions of the currents. 
     
     
         17 . The electrochemical measurement apparatus according to  claim 16 , wherein, on the display portion, the two or more of the images are differentiated by colors, and the colors are additively mixed and displayed on an overlap of the images. 
     
     
         18 . An electrochemical measurement apparatus, comprising:
 an electrolytic solution tank capable of containing an electrolytic solution and a sample that generates or consumes a plurality of measurement target substances in the electrolytic solution;   a plurality of working electrodes arranged in a measurement area, the measurement area being provided on a bottom surface of the electrolytic solution tank, wherein   the plurality of working electrodes comprises a plurality of current measurement working electrodes and a plurality of potential measurement working electrodes, the plurality of current measurement working electrodes and the plurality of potential measurement working electrodes, respectively, being arranged uniformly in the measurement area, such that the current measurement working electrodes and the potential measurement electrodes are mutually mixed in the measurement area;   a counter electrode and a reference electrode both provided in the electrolytic solution tank, a voltage applying portion;   a voltage applying portion having a function of applying a voltage between each of the plurality of current measurement working electrodes and the counter electrode, all simultaneously;   a current measuring portion configured to measure a current that flows between each of the plurality of current measurement working electrodes and the counter electrode; and   a potential measuring portion configured to measure a voltage between each of the plurality of potential measurement working electrodes and the reference electrode;   whereby a distribution in the measurement area of the measured currents and a distribution in the measurement area of potentials of the plurality of potential measurement working electrodes are acquired.   
     
     
         19 . The electrochemical measurement apparatus according to  claim 18 , wherein
 the plurality of current measurement working electrodes further comprises a plurality of current measurement working electrode groups each of which includes a plurality of current measurement working electrodes, the plurality of current measurement working electrodes included by each one of the plurality of current measurement working electrode groups, respectively, being arranged uniformly in the measurement area, such that the working electrodes included by all of the plurality of current measurement working electrode groups are mutually mixed in the measurement area;   the voltage applying portion has a further function of applying the voltage which is determined in accordance with the current measurement working electrode group that includes the current measurement working electrode;   any two current measurement working electrode groups among the plurality of current measurement working electrode groups are mutually different in at least any of the determined voltage, presence/absence of a molecular modification of an electrode surface and a species of the molecular modification; and whereby   a distribution in the measurement area of the measured currents that flow through the current measurement working electrodes included by each one of the plurality of current measurement working electrode groups is acquired.   
     
     
         20 . The electrochemical measurement apparatus according to  claim 19 , wherein the current measurement working electrode included by each of the plurality of current measurement working electrode groups has an electrode area which is determined in accordance with the current measurement working electrode group, and at least two of the current measurement working electrode groups have mutually different electrode areas. 
     
     
         21 . The electrochemical measurement apparatus according to  claim 19 , wherein at least two of the plurality of current measurement working electrode groups are mutually different in density as number of the current measurement working electrodes per unit area of the measurement area. 
     
     
         22 . The electrochemical measurement apparatus according to  claim 19 , wherein a plurality of configuration units are cyclically arranged on the measurement area, the configuration unit being defined as a determined closed plane figure having therein arranged a determined set of working electrodes, the determined set of working electrodes comprising both of all of a respectively determined number of the current measurement working electrode(s) included by each of the plurality of current measurement working electrode groups and another determined number of the potential measurement working electrode(s), wherein the respectively determined number is a positive natural number determined in accordance respectively with each of the plurality of the working electrode groups and another determined number is another positive natural number. 
     
     
         23 . The electrochemical measurement apparatus according to  claim 22 , wherein all the configuration units have a same arrangement pattern of the set of working electrodes in the configuration unit. 
     
     
         24 . The electrochemical measurement apparatus according to  claim 18 , further comprising a data processing portion configured to interpolate at least one of the acquired distribution of the currents at a position where any of the current measurement working electrodes included by the one of the plurality of current measurement working electrode groups does not exist and the acquired distribution of potentials at a position where any of the potential measurement working electrodes does not exist. 
     
     
         25 . The electrochemical measurement apparatus according to  claim 18 , further comprising a display portion configured to overlappingly display two or more of images of the acquired distributions of the currents and an image of the acquired distribution of potentials. 
     
     
         26 . The electrochemical measurement apparatus according to  claim 25 , wherein, on the display portion, the two or more of the images are differentiated by colors, and the colors are additively mixed and displayed on an overlap of the images. 
     
     
         27 . A transducer configured to be used for electrochemical measurement of a plurality of measurement target substances generated or consumed by a sample, comprising:
 an LSI chip;   an electrolytic solution tank which is capable of containing an electrolytic solution and the sample immersed in the electrolytic solution, the electrolytic solution tank being mounted on the LSI chip; and   a plurality of electrodes of the LSI chip which are two-dimensionally arranged in a measurement area provided on a bottom surface of the electrolytic solution tank, wherein   the plurality of electrodes comprises a plurality of types of electrodes each of which includes a plurality of electrodes, the plurality of types of electrodes being mutually differentiated by being different in at least any of a size of an electrode surface, presence/absence of a molecular modification of the electrode surface, and a species of the molecular modification, and wherein   the plurality of electrodes included by each one type of electrodes, respectively, are arranged uniformly in the measurement area, such that the electrodes included by all of the plurality of types of electrodes are mutually mixed in the measurement area.   
     
     
         28 . The transducer according to  claim 27 , wherein a plurality of configuration units are cyclically arranged on the measurement area, the configuration unit being defined as a determined close plane figure having therein arranged a determined set of electrodes, the determined set of electrodes comprising all of a respectively determined number of the electrode(s) included by each of the plurality of types of electrodes, wherein the respectively determined number is a positive natural number determined in accordance respectively with each of the plurality of types of electrodes. 
     
     
         29 . The transducer according to  claim 28 , wherein all the configuration units have a same arrangement pattern of the set of electrodes in the configuration unit.