FET Array Biomolecule Detection via Charge Carrier Aggregation

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Solution Overview

Problem

Current biomolecule detection techniques require adjusting sample concentration, limiting their practicality for early disease diagnosis due to limitations in detection sensitivity and parallel processing capabilities.

Innovation Solution

A method using charge carriers immobilized with antibodies to form aggregates, detected through field-effect transistors with multiple detectors, allowing for high-speed, parallel detection without the need for concentration adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If optical fiber arrays are used for parallel detection, then detection speed is improved, but the number of detectable molecules is limited by the number of optical fibers

Engineering Contradiction:
Improvedetection speedVSAvoidnumber of detectable molecules
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent replaces the optical detection system with an electrical detection system using field-effect transistors. Instead of using optical fibers to detect molecules, the invention uses FETs with gates that directly sense electrical properties of charge carriers bound to antigens, enabling detection of much larger numbers of molecules simultaneously through electrical rather than optical means.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the detection parameter from optical signal measurement to electrical property measurement. By detecting changes in electrical characteristics (such as threshold voltage shifts) of FETs when charge carriers bind to antigens, the system can accommodate and detect a much larger quantity of molecules compared to the physical limitation of optical fiber arrays.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If sample concentration is adjusted in advance, then detection accuracy is improved, but the process becomes more complex

Engineering Contradiction:
Improvedetection accuracyVSAvoidprocess complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The FET-based detection system automatically adapts to different antigen concentrations through its electrical sensing mechanism. The system self-adjusts by measuring threshold voltage shifts or current changes that are naturally proportional to the amount of bound charge carriers, eliminating the need for manual sample concentration adjustment while maintaining detection accuracy across a wide range of concentrations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention creates a universal detection platform that can detect antigens across a wide concentration range (from 10^-19 to 10^-16 M) without requiring different detection protocols or sample preparation steps. The FET array system handles various concentrations through a single, unified electrical measurement approach, making the detection process simpler and more versatile.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If flow cytometry is used to determine microparticle numbers, then molecule counting is achieved, but parallel processing capability is limited

Engineering Contradiction:
Improvemolecule counting accuracyVSAvoidparallel processing capability
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The invention segments the detection function across multiple independent FET devices arranged in arrays. Each FET acts as an independent detection unit that can simultaneously detect antigens in parallel, whereas flow cytometry processes particles sequentially through a single detection channel. This segmentation enables high-speed parallel detection while maintaining accurate molecule counting capabilities.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables the detection of a wide range of biomolecule concentrations from 1 µM to 1 aM, with the ability to count 100,000 charge carrier conjugates per second, reducing the need for optical systems and lowering device production costs.

Implementation Method 1

a method uses a field-effect transistor for detection, and allows the detectors to be easily provided in parallel for easy and high-speed detection

Methodology Applied
Scientific EffectField-effect transistor effect: Electric Field

Data Source

PatentEP2884270B1Biomolecule detection method and biomolecule detection device
Publication Date: 2018.05.30 HITACHI HIGH TECH CORP
  • EP2884270B1 patent drawingFigure 1
  • EP2884270B1 patent drawingFigure 2a~2c
  • EP2884270B1 patent drawingFigure 3

AI summary

The present invention is intended to provide a method and a device for detecting a biomolecule with high sensitivity and high throughput over a wide dynamic range without requiring concentration adjustments of a sample in advance. The present invention specifically binds charge carriers to a detection target biomolecule, and detects the detection target biomolecule one by one by measuring a current change that occurs as the conjugate of the biomolecule and the charge carriers passes through a micropore. High-throughput detection of a biomolecule sample is possible with an array of detectors.