Research On Highly Sensitive Fiber Optic Biosensor Based On Two-Dimensional Materials

Photonic crystal fiber（PCF）sensors based on surface plasmon resonance（SPR）are widely used in the sensing field because of their small size,fast detection speed,and markerless advantages.However,with the continuous research on sensing technology,how to achieve multifunctional detection in complex detection environments has become a hot research topic at the current stage.In this paper,we combine the PCF-SPR sensor and two-dimensional material,and integrate and optimize the material,structure,and light source to solve the three types of problems,such as low detection sensitivity,small detection range and large interference of simultaneous detection of multiple substances,respectively.Combining the designed sensor model with different bioinformatic models,the simulation has obtained better bioinformatic detection data.The main research work and innovations are as follows:（1）To address the problem of low sensor detection sensitivity,a graphene-molybdenum disulfide heterojunction high-sensitivity fiber optic biosensor is proposed.In this study,graphene and molybdenum disulfide heterojunctions were introduced into the D-type PCF sensor,and the maximum wavelength sensitivity and maximum amplitude sensitivity were4700 nm/RIU and 327.5 RIU^-1,respectively.Compared with the model without the addition of graphene-molybdenum disulfide,it showed a 24%improvement in wavelength sensitivity and a 23%improvement in amplitude sensitivity.The sensor detected hemoglobin concentrations in the range of 0 g/L to 241 g/L with an average sensitivity of 0.7 nm/（g/L）.（2）A gold nanowireset fiber optic sensor with a wide detection range of low refractive index is proposed for the problems of small detection range of the sensor and difficult detection of low refractive index.In this study,a gold nanowireset structure with propagating surface plasmon resonance and localized surface plasmon resonance properties were designed.Under the specified conditions,the detection range of the proposed sensor is expanded by 56%and the wavelength sensitivity is increased by 81%compared with the conventional gold thin-layer sensor,which has a detection range of 1.08 to 1.37 and a maximum wavelength sensitivity of 13000 nm/RIU.In addition,the detection related to human volatile organic chemicals is simulated by adding zinc oxide to this sensor.（3）A low-interference multichannel biosensor with simultaneous detection was proposed to address the problem that the sensor cannot achieve simultaneous detection of multiple channels.In this study,independent four-channel,dual-polarized light source,and multiple materials are used to effectively reduce the mutual interference between channels.The maximum wavelength sensitivities of the four channels are 49800 nm/RIU,49000nm/RIU,35900 nm/RIU and 36800 nm/RIU.The interference between the channels is less than 2.69%when the analytes are detected simultaneously by this sensor.The sensor can detect a variety of biological information simultaneously,with a wavelength sensitivity of11500 nm/RIU for normal erythrocytes and 12200 nm/RIU for breast cancer cells MCF-7.