Ion detection device and ion detection method

Patent metadata

Field	Value
Publication number	US-12196703-B2
Application number	US-202017627259-A
Country	US
Kind code	B2
Filing date	May 19, 2020
Priority date	Jul 26, 2019
Publication date	Jan 14, 2025
Grant date	Jan 14, 2025

Abstract

An ion detection device includes an ion sensor having a sensitive film immersed in an aqueous solution and outputting an output signal in accordance with a potential change of the sensitive film, and an adjuster acquiring the output signal of the ion sensor and adjusting a drive signal for driving the ion sensor to reduce an offset from a predetermined reference value in the output signal.

First claim

The invention claimed is:

1. An ion detection device comprising:
an ion sensor having an ion sensitive portion immersed in an aqueous solution and configured to output an output signal in accordance with a potential change of the ion sensitive portion; and
a drive signal adjuster circuit configured to acquire the output signal of the ion sensor and adjust a drive signal for driving the ion sensor to reduce an offset from a predetermined reference value in the output signal,
wherein the drive signal adjuster circuit includes:
a first adjuster circuit configured to receive the output signal and output a signal adjusted in a direction opposite to an offset direction of the output signal; and
a second adjuster circuit configured to generate the drive signal by adjusting a gain of the signal output by the first adjuster circuit component.

2. The ion detection device according to claim 1 ,
wherein the drive signal adjuster circuit is configured to be able to switch between a first operation mode in which the drive signal is adjusted based on the output signal and a second operation mode in which the drive signal adjusted in the first operation mode is maintained.

3. The ion detection device according to claim 1 , further comprising an electrode configured to apply a reference voltage to the aqueous solution,
wherein the drive signal is the reference voltage.

4. The ion detection device according to claim 1 ,
wherein the ion sensor includes:
an injection diode (ID) portion including an injection diode and configured to store an electric charge to be injected into a potential well whose depth changes in accordance with the potential change of the ion sensitive portion; and
an input control gate electrode (ICG) portion including an input control gate electrode and configured to control an amount of the electric charge injected from the ID portion to the potential well,

wherein the ion sensor is configured to inject the electric charge from the ID portion into the potential well by changing a potential of the ICG portion while keeping a potential of the ID portion constant, and
wherein the drive signal is a voltage applied to the ID portion.

5. The ion detection device according to claim 1 ,
wherein the ion sensor includes:
an injection diode (ID) portion including an injection diode and configured to store an electric charge to be injected into a potential well whose depth changes in accordance with the potential change of the ion sensitive portion; and
an input control gate electrode (ICG) portion including an input control gate electrode and configured to control an amount of the electric charge injected from the ID portion to the potential well,

wherein the ion sensor is configured to inject the electric charge from the ID portion into the potential well by changing a potential of the ID portion while keeping a potential of the ICG electrode constant, and
wherein the drive signal is a voltage applied to the ICG portion.

6. The ion detection device according to claim 1 ,
wherein the ion sensor includes a plurality of pixel groups,
wherein each pixel group of the plurality of pixel groups includes one or more pixels each having the ion sensitive portion independently,
wherein the drive signal adjuster circuit is provided for the each pixel group, and
wherein the drive signal adjuster circuit provided in one pixel group is configured to adjust the drive signal common to each pixel included in the one pixel group based on the output signal of the each pixel included in the one pixel group.

7. An ion detection method performed by an ion detection device, the ion detection device comprising an ion sensor having an ion sensitive portion immersed in an aqueous solution with which an inspection target object is brought into contact and configured to output an output signal in accordance with a potential change of the ion sensitive portion, the method comprising:
a first step of acquiring an output signal of the ion sensor and adjusting a drive signal for driving the ion sensor such that an offset from a predetermined reference value in the output signal is reduced before giving a stimulus for inspecting the inspection target object to the aqueous solution or the inspection target object;
a second step of giving the stimulus to the aqueous solution or the inspection target object while maintaining the drive signal adjusted in the first step; and
a third step of detecting an ion concentration of the inspection target object based on the output signal of the ion sensor obtained after the second step,
wherein the ion detection device further comprises a drive signal adjuster circuit including:
a first adjuster circuit configured to receive the output signal and output a signal adjusted in a direction opposite to an offset direction of the output signal; and
a second adjuster circuit configured to generate the drive signal by adjusting a gain of the signal output by the first adjuster circuit component.

8. An ion detection device comprising:
an ion sensor having an ion sensitive portion immersed in an aqueous solution and configured to output an output signal in accordance with a potential change of the ion sensitive portion; and
a drive signal adjuster circuit configured to acquire the output signal of the ion sensor and adjust a drive signal for driving the ion sensor to reduce an offset from a predetermined reference value in the output signal,
wherein the drive signal adjuster circuit is configured to be able to switch between a first operation mode in which the drive signal is adjusted based on the output signal and a second operation mode in which the drive signal adjusted in the first operation mode is maintained.

9. An ion detection device comprising:
an ion sensor having an ion sensitive portion immersed in an aqueous solution and configured to output an output signal in accordance with a potential change of the ion sensitive portion;
a drive signal adjuster circuit configured to acquire the output signal of the ion sensor and adjust a drive signal for driving the ion sensor to reduce an offset from a predetermined reference value in the output signal; and
an electrode configured to apply a reference voltage to the aqueous solution,
wherein the drive signal is the reference voltage.

Assignees

• Hamamatsu Photonics Kk

Inventors

• Mizuno Seiichiro
• Yamamoto Hiroo
• Morita Sho
• WAKAMORI Toshiki

Classifications

• G01N27/4148 Primary

  Integrated circuits therefor, e.g. fabricated by CMOS processing · CPC title

• G01N27/413

  Concentration cells using liquid electrolytes {measuring currents or voltages in voltaic cells} · CPC title

• G01N27/002

  by investigating the work function voltage · CPC title

• G01N27/414

  Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS · CPC title

• G01N27/301 Primary

  Reference electrodes · CPC title