ITO-based laminated SPR biosensor chip

Abstract

The invention provides an ITO-based laminated SPR biosensor chip, which comprises a glass substrate, a silver layer, an ITO layer and a gold layer which are sequentially arranged, the glass substrate is made of a BK7 material with high refractive index, the thickness of the glass substrate is about 1mm, the thickness of the silver layer is between 10nm and 30nm, the thickness of the ITO layer is between 20nm and 50nm, and the thickness of the gold layer is between 5nm and 20nm. According to the invention, the problem that preparation and coating are difficult to control when graphene is used as a sensitizing material can be avoided, so that a relatively mature semiconductor material ITO is turned to, and the preparation cost of a high-sensitivity chip is reduced; by means of the conductivity of ITO and the performance of a semiconductor, the chip has higher sensitivity; and the outermost gold layer can play a role in protecting the ITO from mildewing.

Description

technical field [0001] The invention relates to the field of SPR sensors, in particular to an ITO-based laminated SPR biosensor chip. Background technique [0002] Surface Plasmon Resonance (SPR) is a technical method that uses the photoelectric effect to detect changes in the refractive index of substances. In theory, any phenomenon that can cause changes in the refractive index can be monitored and recorded by SPR. Therefore, SPR sensors are widely used in the fields of food, medicine, biomedicine and gas detection due to their ultra-high sensitivity. [0003] Resonance occurs when the wave vector of the incident light wave along the interface coincides with the propagation vector of the surface plasmon wave (SPW), at which point the incident light wave is absorbed sharply and the reflected light wave decreases. The more the incident light wave is absorbed, the less the reflected light wave is, indicating that the resonance is more intense and the effect of the chip is be...

AI Technical Summary

Problems solved by technology

In order to improve the sensitivity of the SPR sensor chip, people have made many attempts, including changing the structure and adding new materials. The current mainstream method of enhancing SPR is to coat graphene on the gold or silver layer to enhance its propagation coefficient and improve sensitivity. However, graphene has high requirements in terms of preparation and coating methods, and at the same time, it is difficult to control the coating quality

[0004] It can be seen that the current means for improving the resonance of surface plasmon sensor chips is mainly to coat graphene on the chip. The preparation and coating of single-layer graphene require high technical means, and the quality is difficult to control. cost of preparation

At the same time, it is difficult to greatly improve the sensitivity and quality of the chip by simply changing the gold layer into a silver layer and replacing graphene with ITO.

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