Near-infrared biosensor capable of tuning penetration depth and adopting memristor reconstruction, and method

Abstract

The invention provides a near-infrared biosensor capable of tuning the penetration depth and adopting memristor reconstruction, and a method. The sensor comprises a prism unit, a first non-conductivemedium thin film layer, a metal thin film layer, a second non-conductive medium thin film layer and a conductive medium thin film layer; the prism unit is used for generating ATR attenuation evanescent waves; the first non-conductive medium thin film layer, the metal thin film layer and the second non-conductive medium thin film layer constitute a sensing unit to achieve the basic sensing function; the metal thin film layer, the second non-conductive medium thin film layer and the conductive medium thin film layer constitute a memristor unit; and a voltage applying device is further arranged and used for applying the bias voltage to the memristor unit to achieve infrared memristor reconstruction. The invention further provides a preparation method of the sensor and the penetration depth tuning method. The penetration depth generated by the sensing unit of the biosensor is dynamically changed when the bias voltage is applied to the memristor unit, the penetration depth is tuned, and theresolution ratio of the biosensor can be obviously increased when unknown material organisms are detected.

Description

technical field [0001] The invention relates to the technical field of surface plasmon resonance biosensors, in particular to a tunable penetration depth biosensor, in particular to a memristive reconstruction near-infrared tunable penetration depth biosensor and a method thereof. [0002] technical background [0003] Surface plasmon resonance (SPR) is an optical phenomenon, which was discovered by Wood in the early 20th century. In the early days, plasmon resonance was generated by bombarding the metal surface with electron beams in vacuum. In the 1960s, two scientists from West Germany, Otto and Kretchmann, respectively invented the method of exciting surface ions by visible light. It was not until the 1980s that Liedberg, a scientist from Sweden, used this technology to detect the interaction between biomolecules. . [0004] Surface plasmon polaritons (SPPs) are the key to generate SPR, which are free charge oscillations generated under a specific optical wave field at t...

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Problems solved by technology

[0008] (1) The traditional SPR surface plasmon wave decays exponentially along the normal direction of the interface, and the effective penetration depth is only about 300nm. Although this characteristic is very sensitive to the change of the refractive index near the interface, it cannot be realized against viruses, bacteria, Effective detection of macromolecules such as proteins, and the traditional surface plasmon resonance technical indicators have reached the bottleneck, it is difficult to improve

[0009] (2) The LRSPR biosensor introduces a dielectric buffer layer between the prism and the metal layer of the traditional SPR biosensor. When the refractive index of the dielectric buffer layer and the analyte are equal, a symmetrical environment is realized, so that the SPW (surface plasmon wave , propagated by SPPs oscillations) has a propagation length exceeding that of conventional SPWs and preserves the energy of the incident beam. The advantage is that LRSPR devices have very sharp (i.e., large depth-to-width ratio) reflectivity, and special LRSPR biosensors The structural penetration depth can reach more than 3um, and the disadvantage is that it depends on the existence of a symmetrical environment

[0010] (3) The CPWR biosensor is combined with the waveguide layer below the surface of the traditional SPR biosensor. The interference of the waveguide layer in the CPWR device causes a steep dip angle in both the longitudinal (TM) and transverse (TE) modes. The advantage is that it has a better Depth-width ratio and can reach a penetration depth of 2um. The disadvantage is that there is a considerable distance between the biosensing surface and the SPW at the interface between the metal film and the waveguide layer, and its sensitivity is still about 10 times lower than that of traditional SPR devices.

However, for different analytes such as proteins, bacteria, dispersed cells, and living cells of different sizes, especially for larger unknown biochemical materials, the ATR attenuation evanescent wave generated by the sensor with a fixed penetration depth can only be partially sensed Organisms, not all information available

On the contrary, when a sensor with a larger penetration depth is used to sense a small-sized organism, the resonantly enhanced surface plasmon wave will pass through the object to be tested and penetrate into the external environment, resulting in greater external interference, and at the same time, the resolution will increase. reduce

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