Electrical SPR Sensor Chip With Direct Current Readout
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Solution Overview
Problem
Conventional surface plasmon resonance sensors face challenges in reducing size, achieving high throughput, and maintaining sensor accuracy due to the need for precise control of metal fine particles and the involvement of oxidation and reduction reactions, which affect sensor sensitivity and accuracy.
Innovation Solution
A surface plasmon resonance sensor chip configuration featuring a prism, a transparent electrode, an n-type transparent semiconductor film, and a plasmon resonance film electrode, where incident light is converted into surface plasmon polaritons that can be directly detected as an electric signal, allowing for accurate measurement of refractive index changes and sample concentration or state changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical system is used to detect surface plasmon resonance angle changes, then measurement precision is improved, but device complexity and size increase, making integration difficult and throughput low
Solution Approach 1:
The patent replaces the optical detection system with an electrical measurement system. Specifically, it substitutes the optical system that measures surface plasmon resonance angle changes with an electrical measurement system that detects current changes. The sensor chip includes a metal fine particle layer on a substrate, where surface plasmon resonance generates electrical signals (current changes) that can be directly measured without complex optical components, thereby simplifying device structure while maintaining measurement capability
Solution Approach 2:
The patent extracts and eliminates the complex optical detection system from the sensor configuration. By focusing only on the essential metal fine particle layer and substrate combination, it removes the need for bulky optical components, enabling compact integration and high-throughput processing while preserving the core surface plasmon resonance detection function through electrical measurements
2Volume of moving object
If metal fine particles are used for localized surface plasmon resonance, then sensor miniaturization is achieved, but manufacturing precision requirements increase and detection signal intensity is insufficient
Solution Approach 1:
The patent changes the detection parameter from optical absorbance to electrical current measurement. By measuring current changes instead of optical absorbance, it overcomes the limitation of weak detection signals while maintaining the miniaturized metal fine particle structure. This parameter change allows the use of simpler manufacturing processes for the metal particles while achieving sufficient detection sensitivity through electrical measurements
3Measurement precision
If photoelectric conversion elements with metal fine particles are used, then sensor sensitivity is improved, but oxidation and reduction reactions of the electrolyte occur, affecting measurement accuracy
Solution Approach 1:
The patent introduces an n-type transparent semiconductor film as an intermediary layer between the metal fine particle layer and the electrolyte. This intermediary layer prevents direct contact between the metal particles and the electrolyte, thereby eliminating oxidation and reduction reactions that would otherwise occur. The semiconductor layer acts as a protective barrier that maintains measurement accuracy by preventing harmful chemical reactions while still allowing the surface plasmon resonance effect to be detected through current changes
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
This configuration enables a compact, high-throughput surface plasmon resonance sensor with enhanced sensitivity and accuracy, capable of detecting changes in refractive index and sample state without affecting the sample, thus improving sensor performance.
Implementation Method 1
Surface plasmon resonance (SPR) is a state in which free electrons are in collective oscillatory motion (plasma oscillation) on a metal surface... the interaction between the incident light and the electric field produced around the free electrons under plasma oscillation... an electron compression wave (surface plasmon polariton, SPP) formed by the coupling of the plasma oscillation and the electromagnetic wave traveling along the interface propagates along the metal surface
Implementation Method 2
anode electrode in which a transparent electrode layer, a metal microparticle layer, a semiconductor thin film made of n-type semiconductor, and a pigment adsorption layer are stacked... improve the efficiency of photoelectric conversion in photoelectric conversion elements
Data Source
Figure 1A~1B
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AI summary
An electricity measuring type surface plasmon resonance sensor comprising: a plasmon polariton intensifying sensor chip in which a prism and a sensor chip including a transparent electrode, an n-type transparent semiconductor film, and a plasmon resonance film electrode arranged in this order are arranged in an order of the prism, the transparent electrode, the n-type transparent semiconductor film, and the plasmon resonance film electrode; and an electric measuring apparatus which directly measures a current or voltage from the transparent electrode and the plasmon resonance film electrode.