JPH09210958A - Optical scanning two-dimensional sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scanning two-dimensional sensor which will never disturb the overall distribution of potential. SOLUTION: An optical scanning two-dimensional sensor concerned is composed of the first electrode 1 light transmissive, a photo-conductive layer 4 which is installed in contact with one surface of the first electrode 1 and exhibits electroconductivity only in its part irradiated with light directly, a functional responsive layer 5 which is formed on the oversurface of the photo- conductive layer 4, and the second electrode 7 which is installed in such a condition as apart from the functional responsive layer 5. A voltage is impressed between the first and second electrodes 1 and 7 in the condition that a specimen to be measured 6 is placed between the layer 5 and the second electrode 7 in contact therewith, and when the other surface of the first electrode 1 is irradiated with a scanning beam of light 10, the photo-conductive layer 4 exhibits a low conductivity only in its irradiated part, and thus sensing of the specimen to be measured 6 is made by the responsive layer 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning type two-dimensional sensor.

[0002]

2. Description of the Related Art One of optical scanning two-dimensional sensors is disclosed in, for example, Jpn. J. Appl. Phys. Vol. 33
As described in (1994) pp L394-397, a silicon (Si) substrate on which a sensor surface made of a pH responsive film such as Si ₃ N ₄ is formed is scanned with an appropriate modulated light, and this scan is performed. Optical scanning two-dimensional p that measures by extracting the photocurrent generated in the substrate
There is an H distribution measuring device.

In such an optical scanning type two-dimensional pH distribution measuring apparatus, when the measurement sample such as a solution is inserted between the sensor surface composed of the pH responsive film and the upper electrode, the measurement sample and the pH are measured. A potential difference according to pH is generated at the interface with the responsive membrane, and a photocurrent flows according to the potential difference in the portion corresponding to the area of the irradiated light, and this can be taken out to the outside. The distribution of the potential difference generated at the interface with
A distribution image can be obtained.

[0004]

However, in the above-mentioned optical scanning type two-dimensional pH distribution measuring apparatus, a measurement sample such as a solution, a sensor surface typified by a pH responsive film, a photocarrier is generated, and a current is generated. Since the Si substrate from which the light is extracted is electrically separated, it depends only on the MOS structure composed of the measurement sample and the oxide film or the sensor surface provided on the oxide film and the Si substrate. There are drawbacks.

That is, it is not possible to control an accurate electric potential on the interface, particularly on the interface between a solid and a liquid such as a response film. The electric current generated by the chemical reaction at the interface cannot be extracted. When a chemical reaction occurs at the interface, basically, it is possible to know only the relative potential fluctuation due to the potential generated by the chemical reaction disturbing the entire potential distribution with respect to the potential gradient determined from the outside. You can only. It is impossible to know the distribution of general electrical characteristics such as the electric potential, resistance, and impedance other than the potential and electric capacity of the measurement sample. Light needs to be modulated, and potential fluctuations faster than the modulation frequency cannot be measured. The photocarrier is a characteristic of the physical properties of the semiconductor itself and is limited by the specific resistance and the like, so the amount of current is limited by the semiconductor material.

The present invention has been made in view of the above matters, and an object thereof is to provide an optical scanning type two-dimensional sensor having a novel structure which has never existed before.

[0007]

In order to achieve the above object, in the present invention, the photo-responsive mechanism is replaced with a conventional method of detecting a current by a photo carrier inside a semiconductor, and a photo-conductive layer is provided to irradiate light. The method is based on photoconductivity.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A first optical scanning type two-dimensional sensor of the present invention is provided in contact with a light-transmissive first electrode portion and one surface of the first electrode portion, and irradiates light. A photoconductive layer showing conductivity only in a portion directly received, a functional response layer formed on the upper surface of the photoconductive layer, and a second electrode portion provided in a state separated from the functional response layer, A voltage is applied between the first electrode portion and the second electrode portion while the measurement sample is in contact with both of the functional response layer and the second electrode portion, and the other of the first electrode portion is applied. It is characterized in that the photoconductive layer exhibits low conductivity only in the light-irradiated portion when the light is irradiated while scanning from the surface, and the functional response layer can sense the measurement sample.

In the first optical scanning two-dimensional sensor having the above structure, when light is irradiated from the other surface of the first electrode portion, only the light-irradiated portion of the photoconductive layer has a remarkably low resistance. Therefore, a voltage is locally applied to the measurement sample that is in contact with the irradiated area portion through the functional response layer. Therefore, by sequentially changing the light irradiation position on the photoconductive layer and scanning the entire surface of the photoconductive layer, it is possible to locally apply a voltage locally to the functional response layer and the measurement sample. And the current corresponding to the voltage applied to the measurement sample can be extracted to the outside as the current of the part corresponding to the area of the irradiation light, and based on this, the mutual reaction between the functional response layer at the interface and the measurement sample can be performed. A two-dimensional current distribution image based on it can be obtained, and the measurement sample can be sensed.

In the first optical scanning two-dimensional sensor, a metal layer having an island-shaped electrode portion in a fine area may be provided on the upper surface of the functional response layer. In this case, the surface of the metal layer becomes a uniform equipotential surface, so that potential control can be stably performed.

The second optical scanning type two-dimensional sensor of the present invention is provided in contact with the light-transmissive first electrode portion and one surface of the first electrode portion, and directly receives light irradiation. The ion responsive film is composed of a photoconductive layer showing conductivity only in the above-mentioned portion, an ion responsive film provided on the upper surface of the photoconductive layer, and a second electrode portion provided in a state separated from the ion responsive film. The measurement sample is placed between the second electrode section and the second electrode section so as to contact them, and when the light is applied while scanning the light from the other surface of the first electrode section, the photoconductive layer is lowered in the light irradiation section. It becomes a resistance, and the potential difference generated at the interface between the ion-responsive film corresponding to the light irradiation portion and the measurement sample can be measured from the outside.

In the second optical scanning two-dimensional sensor having the above structure, when light is irradiated from the other surface of the first electrode portion, only the light-irradiated portion of the photoconductive layer has a remarkably low resistance. Therefore, the measurement circuit can be connected to the ion-responsive film and the measurement sample that are in direct contact with the irradiated area. Therefore, by sequentially changing the light irradiation position on the photoconductive layer and scanning the entire surface of the photoconductive layer, the ion responsive film and the measurement sample can be sequentially switched to function, and the ion concentration in the measurement sample can be improved. Accordingly, the potential difference generated at the interface between the ion-responsive membrane and the measurement sample can be taken out, and based on this,
A two-dimensional density distribution image at the interface can be obtained.

In the conventional optical scanning type two-dimensional sensor,
Photo-carriers are generated in the semiconductor by being induced by light irradiation, and these photo-carriers are taken out as a current.The photo-carriers are determined by the lifetime of the semiconductor material and the specific resistance. It becomes the signal amount. Therefore, the image resolution and S / N are determined by the physical properties and thickness of the substrate material.

On the other hand, in the second optical scanning two-dimensional sensor, since it can be applied to an insulating film, it is possible to obtain a distribution image of electrochemical characteristics in a solution such as pH and various ion concentrations. .

In the second optical scanning two-dimensional sensor, a conductive layer having a plurality of island-shaped electrode portions may be provided between the photoconductive layer and the ion responsive film.

Furthermore, the third optical scanning type two-dimensional sensor of the present invention is provided in contact with the light-transmissive first electrode portion and one surface of the first electrode portion, and directly receives light irradiation. And a second electrode portion provided in a state of being separated from the photoconductive layer, and a measurement sample is provided between the photoconductive layer and the second electrode portion. A voltage is applied between the first electrode portion and the second electrode portion while being in contact with the first electrode portion, and light is emitted while scanning the light from the other surface of the first electrode portion. It has a feature.

In the third optical scanning two-dimensional sensor having the above structure, when light is irradiated from the other surface of the first electrode portion, only the light-irradiated portion of the photoconductive layer has a remarkably low resistance. Therefore, the voltage is locally applied to the measurement sample that is in direct contact with the irradiated area portion. Therefore, by sequentially changing the light irradiation position and scanning the entire measurement sample, it is possible to locally apply a voltage locally to the measurement sample, and to irradiate a current according to the voltage applied to the measurement sample. A current corresponding to the area of light can be extracted to the outside, and based on this, a two-dimensional current distribution image at the interface can be obtained.

In the third optical scanning two-dimensional sensor, a metal layer having an island-shaped conductive portion in a fine area may be provided on the upper surface of the photoconductive layer. In this case, the surface of the metal layer becomes a uniform equipotential surface, so that potential control can be stably performed.

In the third optical scanning type two-dimensional sensor, an enzyme electrode may be provided on the upper surface of the photoconductive layer. In this case, the current generated by the reaction between the measurement sample and the enzyme is measured. be able to.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an optical scanning type two-dimensional sensor of the first embodiment. In FIG. 1, reference numeral 1 denotes a light-transmissive first electrode portion, which includes a light-transmissive substrate 2 and a light-transmissive electrode (lower electrode) 3. In this embodiment, a glass plate is used as the light transmissive substrate 2, and the lower electrode 3 is made of, for example, In ₂
ITO made by mixing O ₃ and SnO ₂ in an appropriate ratio
(Transparent conductive film).

Reference numeral 4 denotes a photoconductive layer formed on the upper surface of the lower electrode 3 of the first electrode portion 1. The photoconductive layer 4 is conductive only in the portion directly irradiated with light. , For example, amorphous silicon (α-Si) at 300 to 350 ° C.
Formed by processing at a temperature of.

A functional response layer 5 is provided so as to be in close contact with the upper surface of the photoconductive layer 4, and its physical properties are changed by mutual reaction with solid, liquid, gas and the like.

Reference numeral 6 is a measurement sample, which is a layer of solid, liquid, gas or the like, which is interposed between the functional response layer 5 and a second electrode portion 7 described later, and is in close contact with both of them. .

Reference numeral 7 denotes a second electrode portion as an upper electrode, which is provided so as to be in close contact with the upper surface of the measurement sample 6. The configuration and material of the second electrode portion 7 differ depending on the measurement content of the measurement sample 6. That is, when performing electrochemical measurement, the second electrode portion 6 is used as a reference electrode (for example, Ag / AgCl).
An electrode) and a counter electrode (eg, a Pt electrode). Further, in the case of performing general electric characteristics, it is a metal thin film electrode such as Au, Al, Ag, Cu or a printed circuit board formed on the substrate. In this example, it is a metal thin film electrode.

Reference numeral 8 is a DC power source connected between the lower electrode 3 and the upper electrode 7, and 9 is an on / off switch. A laser beam 10 is a probe beam emitted from the glass substrate 2 side of the first electrode unit 1 toward the photoconductive layer 4, and is scanned in the XY directions by a scanning mechanism (not shown). Reference numeral 11 denotes a CPU as a signal processing unit that processes a current signal taken out from the lower electrode 3.

A measuring method using the optical scanning type two-dimensional sensor constructed as described above will be explained. As shown in FIG.
In the state where the thin film is closely mounted as the measurement sample 6 on the upper surface of the functional response layer 5 and the upper electrode 7 made of a thin film electrode is further closely mounted on the upper surface of the measurement sample 6, the switch 9 is closed to close the lower electrode 3 When a DC voltage is applied as a bias voltage between the upper electrode 7 and the upper electrode 7, and the laser light 10 is emitted from the glass substrate 2 side of the first electrode portion 1 toward the photoconductive layer 4, the photoconductive layer 4 Only the portion irradiated with the laser light 10 (the portion indicated by reference numeral 4a in the figure) becomes conductive, and the resistance becomes extremely low. As a result, a voltage is applied to the functional response layer 5 and the portion of the measurement sample 6 (the portions indicated by reference numerals 5a and 6a in the figure) corresponding to the irradiated portion 4a.

By scanning the entire measurement sample 6 while sequentially changing the irradiation position of the laser beam 10, it is possible to apply an electric field to each of the functional response layer 5 and the measurement sample 6 locally. By extracting a current corresponding to the electric field applied to the measurement sample 6 from the lower electrode 3 to the outside as a current of a portion corresponding to the area of the irradiation light,
The current distribution at the interface between the functional response layer 5 and the measurement sample 6 can be sequentially taken out, and this current signal is converted into a voltage and then processed by the CPU 11, so that the interface between the functional response layer 5 and the measurement sample 6 is processed. A two-dimensional current distribution image is obtained.

FIG. 2 shows an optical scanning type two-dimensional sensor of the second embodiment. In the optical scanning type two-dimensional sensor of this embodiment, as shown in FIG. 1A, the first electrode portion 1 is composed of a substrate 12 made of Si for transmitting infrared light and a lower electrode 3 made of ITO. A photoconductive layer 13 formed by treating PbS exhibiting photoconductivity at a temperature of 300 to 350 ° C. is provided on the upper surface of the lower electrode 3. A plurality of island-shaped electrode portions 14 are formed on the upper surface of the photoconductive layer 13.
And a conductive layer 16 composed of an insulating portion 15 for insulating between them
Is provided. As shown in FIG. 3B, the conductive layer 16 is formed by vertically and horizontally forming a plurality of island-shaped electrode portions 14 made of, for example, Pt, which are slightly smaller than the diameter of the irradiated laser 10. Yes, S between the island-shaped electrode portions 14
It is insulated by an insulating portion 15 made of an oxide such as iO ₂ . The other configuration is the same as that of the first embodiment.

A measuring method using the optical scanning type two-dimensional sensor configured as described above will be explained. As shown in FIG.
In a state where the measurement sample 6 is placed on the upper surface of the functional response layer 5 in close contact and the upper electrode 7 made of a thin film electrode is placed on the upper surface of the measurement sample 6 in close contact, the switch 9 is closed to close the lower electrode 3 and the upper portion. A DC voltage is applied between the electrode 7 and the photoconductive layer 13 from the glass substrate 2 side of the first electrode portion 1.
When the laser beam 10 is emitted toward, the resistance of only the portion of the photoconductive layer 13 which is irradiated with the laser beam 10 (the portion indicated by the reference numeral 13a in the drawing) has a remarkably low resistance. As a result, a voltage is applied to the functional response layer 5 and the portions 5a and 6a of the measurement sample 6 corresponding to the irradiated portion 13a.

By scanning the entire measurement sample 6 while sequentially changing the irradiation position of the laser beam 10, it is possible to apply an electric field to each of the functional response layer 5 and the measurement sample 5 locally. A current corresponding to the electric field applied to the measurement sample 5 is taken out from the lower electrode 3 to the outside as a current of a portion corresponding to the area of the irradiation light, so that the current distribution at the interface between the functional response layer 5 and the measurement sample 6 Can be sequentially taken out, and this current signal is subjected to voltage conversion and then processed in the CPU 11 to obtain a two-dimensional current distribution image at the interface between the functional response layer 5 and the measurement sample 6.

Usually, the laser light 10 to be irradiated has an intensity distribution, and exhibits a resistance distribution corresponding to the intensity distribution inside the photoconductive layer 13. Therefore, although a uniform electric field distribution is not shown at the interface between the functional response layer 5 and the measurement sample 6, by providing the conductive layer 16 including a plurality of island-shaped electrode portions 15 having a size smaller than the beam diameter of the laser light 10. The electrode portion 15 of the portion irradiated with the laser light 10 shows a constant potential distribution as a whole. In this case, since the surface of the electrode part 15 is an equipotential surface, precise potential control at the interface can be performed.

In this embodiment, although not shown, the measurement sample 6 was prepared by providing an enzyme electrode on the photoconductive layer 13 or the island-shaped electrode portion 14 of the conductive layer 16.
Current can be measured by the reaction between the enzyme and the enzyme, and a two-dimensional enzyme reaction image can be obtained by using the two-dimensional biosensor. Further, it is possible to perform two-dimensional measurement of a chemical reaction such as a chemical reaction at an interface or a titration state. In particular, when the island-shaped electrode portion 14 is made of Pt, a two-dimensional distribution of redox potential can be obtained.

FIG. 3 shows an optical scanning type two-dimensional sensor of the third embodiment.
Show the service. The optical scanning two-dimensional sensor of this embodiment has a first
The electrode part 1 includes a glass substrate 2 and a lower electrode 3 made of ITO.
The upper electrode of the lower electrode 3 is made of α- which exhibits photoconductivity.
Formed by treating Si at a temperature of 300-500 ° C
A formed photoconductive layer 4 is provided. And this light
An insulating ion-responsive film 17 is formed on the upper surface of the electrically conductive layer 4.
Have been. This ion-responsive film 17 is used for pH measurement, for example.
For Si_ThreeN_FourOr double-layered Si_ThreeN _Four/ Si
O_TwoConsisting of 18 is an upper electrode, and in this embodiment,
Consists of a reference electrode. 19 is a solution as a measurement sample
Therefore, it is schematically shown in the figure. The other configurations are the first
This is the same as the embodiment.

The measurement method using the optical scanning two-dimensional sensor having the above-described structure will be described. When the optical scanning two-dimensional sensor is inserted into the solution 19 as the measurement sample, the ion-responsive film 17 and the upper electrode 18 are formed. During this time the solution 19 is filled. Then, in this state, the switch 9 is closed to connect between the lower electrode 3 and the reference electrode of the upper electrode 18, and further, from the glass substrate 2 side of the first electrode portion 1 to the photoconductive layer 4.
When the laser light 10 is emitted toward, only the portion of the photoconductive layer 4 which is irradiated with the laser light 10 exhibits the optical switch function, and the resistance is remarkably low. As a result, the ion responsive film 17 and the solution 19 that are in direct contact with the irradiated portion are
The potential difference at the interface with and can be taken out as a signal.

Then, by sequentially changing the irradiation position of the laser beam 10 and scanning the entire solution 19, each local part of the solution 19 can function as an optical switch, and at the interface between the ion responsive film 17 and the solution 19. By extracting the potential difference in the portion corresponding to the area of the irradiation light from the lower electrode 3 to the outside, the solution 19 and the ion responsive film 17 are extracted.
The potential distribution at the interface with
By processing this potential signal in the CPU 11, a two-dimensional potential distribution image at the interface can be obtained, whereby a two-dimensional distribution of pH in the solution 19 can be obtained.

As described above, according to the optical scanning type two-dimensional sensor of the third embodiment, the pH of the solution 19 can be measured and its two-dimensional distribution can be obtained. Various ion concentration measurements can be performed by appropriately changing the configuration. The ion responsive membrane will be exemplified below. There are Ta ₂ O ₅ , Al ₂ O ₃ , valinomycin, neutral carrier, PVC (polyvinyl chloride) containing other ion-responsive substances as components, silicone resin and other photosensitive resins.

FIG. 4 shows an optical scanning type two-dimensional sensor of the fourth embodiment. In the optical scanning type two-dimensional sensor of this embodiment, the substrate 20 in the first electrode portion 1 is made of a transparent conductive plastic film. This configuration is advantageous because when α-Si is used as the photoconductive layer 4, it can be formed at a low temperature.

When the photoconductive material itself transmits light, it may be directly irradiated with light. Light reflection at the interface is convenient when observing the photoelectrode reaction, but in general, there is also a case where another reaction called the photoelectrode reaction at the photo-semiconductor interface is observed. Is not preferable when the measurement sample and the measurement sample are in direct contact with each other. In such a case, it may be better to separately provide a metal layer on the upper part.

FIG. 5 shows an optical scanning type two-dimensional sensor of the fifth embodiment. The optical scanning two-dimensional sensor of this embodiment is obtained by removing the functional response layer 5 from the configuration of the optical scanning two-dimensional sensor of the first embodiment. According to the optical scanning two-dimensional sensor configured in this way, the surface distribution of the insulation strength of the highly insulating thin film can be measured. The insulating film includes an oxide insulating film, a ferroelectric thin film, an insulating film formed by a semiconductor device, an insulating film such as polyimide, and a general plastic thin film. Thus, when the measurement sample 6 is an insulating film, a pinhole in the thin film can be detected as a result.

Further, according to the optical scanning type two-dimensional sensor of this embodiment, it is possible to measure the surface distribution of the resistance or the specific resistance of the resistance thin film. The resistance film is a semiconductor thin film, an oxide thin film,
In addition to ferroelectric thin films, insulating films made by semiconductor devices, and insulating films such as polyimide, there are general plastic thin films.

The measurement sample 6 is not necessarily limited to a thin film, and a thick film can be measured. In addition, not only the current display but also a constant voltage is applied to the measured physical property display, so that it is possible to display a general electrical characteristic distribution such as current, resistance, impedance other than the potential.

Further, the measurement sample 6 is not limited to a solid, but may be a liquid or a gas body.

The present invention is not limited to the above-described embodiments, but can be modified in various ways. For example, as the substrate that constitutes the first electrode portion 1, in addition to those listed in the above-described examples, sapphire, quartz, other oxide substrates, infrared transmitting materials such as Ge, and various plastics can be used. Then, as the lower electrode 3, in addition to ITO, a thin film metal or the like can be used.

The first electrode portion 1 may be made of a material that also serves as a substrate and an electrode. In this case, various semiconductor materials such as Si, Ge, and semiconductor oxides can be used. It is necessary to provide an ohmic electrode for this purpose.

The materials for the photoconductive layers 4 and 13 are not limited to those listed in the above-mentioned embodiments, and there are many materials. First, as an inorganic material, amorphous selenium (α-Se), CdS, chalcogenite, Ge, Sn,
There are thin film layers such as CdSe and PbS, and mixed thin film layers of these fine powder components alone or with a binder.

As the organic material, organic polysilane, polyvinylcarbazole, tetrafluorenone, polyphenylene sulfide (PPS), phthalocyanine, a complex in which a metal ion is coordinated in a porphyrin ring (titanyl phthalocyanine dye, Cu-phthalocyanine, x Type metal-free phthalocyanine), polycarbonate, merocyanine dye, dichlorquinacridone, 4,10-dibromoanthanthrone (DBAA), and the like, and thin film layers of these alone or a composite fine powder component and a binder.

Furthermore, the configuration of the second embodiment, that is, the provision of the conductive portion 16 composed of the plurality of island-shaped electrode portions 14 on the side of the photoconductive layer on which the sample is to be measured may be adopted in other embodiments. Good.

[0048]

The present invention is embodied in the above-described embodiment and has the following effects.

The electric current generated by the chemical reaction generated at the interface can be taken out. In such a case, basically, with respect to a potential gradient determined from the outside, the potential fluctuation can be known without disturbing the entire potential distribution by the potential generated by the chemical reaction. Then, two-dimensional measurement of the chemical reaction can be performed by using the chemical reaction at the interface, titration, or using a biosensor with an enzyme electrode.

It is possible to know the distribution of general electrical characteristics such as current, resistance and impedance other than the potential of the measurement sample. When the measurement sample is an insulator layer, pinhole detection can be performed.

The bias voltage can be freely selected and its application range is wide.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of an optical scanning two-dimensional sensor of a first embodiment.

FIG. 2 is a diagram schematically showing a configuration of an optical scanning two-dimensional sensor of a second embodiment.

FIG. 3 is a diagram schematically showing a configuration of an optical scanning type two-dimensional sensor of a third example.

FIG. 4 is a diagram schematically showing a configuration of an optical scanning type two-dimensional sensor of a fourth example.

FIG. 5 is a diagram schematically showing a configuration of an optical scanning type two-dimensional sensor of a fifth example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st electrode part, 2 ... Light transmissive substrate, 3 ... Light transmissive electrode, 4 ... Photoconductive layer, 5 ... Functional response layer, 6 ... Measurement sample,
7 ... 2nd electrode part, 10 ... Laser beam, 12 ... Light transmissive substrate, 13 ... Photoconductive layer, 14 ... Island-shaped electrode part, 16 ... Conductive layer, 17 ... Ion responsive film, 18 ... Second electrode part , 19 ... Measurement sample, 20 ... Light transmissive substrate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Nomura 2 Higashimachi, Kichijoin Miya, Minami-ku, Kyoto-shi, Kyoto

Claims (6)

[Claims] 1. A light-transmissive first electrode portion, and a photoconductive layer provided in contact with one surface of the first electrode portion and having conductivity only in a portion directly irradiated with light, A functional response layer formed on the upper surface of the photoconductive layer and a second electrode portion provided in a state of being separated from the functional response layer, and a measurement sample is provided between the functional response layer and the second electrode portion. A photoconductive layer when a voltage is applied between the first electrode portion and the second electrode portion while being in contact with the second electrode portion, and light is emitted while scanning from the other surface of the first electrode portion. Shows a low electrical conductivity only in the light-irradiated portion, and is configured so that the measurement sample can be sensed by the functional response layer. 2. A light-transmissive first electrode portion, a photoconductive layer which is provided in contact with one surface of the first electrode portion and has conductivity only in a portion which is directly irradiated with light, and An ion responsive film provided on the upper surface of the photoconductive layer and a second electrode portion provided in a state of being separated from the ion responsive film, and a measurement sample is provided between the ion responsive film and the second electrode portion. The photoconductive layer has a low resistance at the light-irradiated portion when the light is irradiated while scanning the light from the other surface of the first electrode portion, so that the measurement is performed with the ion-responsive film corresponding to the light-irradiated portion. An optical scanning two-dimensional sensor characterized in that it is configured so that the potential difference generated at the interface with the sample can be measured from the outside. 3. A light-transmissive first electrode portion, a photoconductive layer which is provided in contact with one surface of the first electrode portion and is conductive only in a portion which is directly irradiated with light, The second electrode portion is provided in a state of being separated from the photoconductive layer, and the measurement sample is brought into contact with the first electrode portion between the photoconductive layer and the second electrode portion. An optical scanning two-dimensional sensor characterized in that a voltage is applied between the second electrode section and the other surface of the first electrode section is irradiated with light while scanning. 4. The optical scanning type two-dimensional sensor according to claim 1, wherein the first electrode portion comprises a light transmissive substrate and a light transmissive electrode. 5. The optical scanning type two-dimensional sensor according to claim 1, wherein the first electrode portion is made of a material that serves as both a substrate and an electrode. 6. The optical scanning two-dimensional sensor according to claim 1, wherein a conductive layer including a plurality of island-shaped electrode portions is provided on the upper surface of the photoconductive layer.