Construction And Performance Study Of High-performance Optical Biosensor Based On Micro-nano Structures

Optical biosensors are devices used to detect changes in the state of a biological sample by optical signals.In recent years,with the immense development of nanotechnology,it becomes possible to design and manufacture a new generation of high-performance micro-nano biosensors by combining new nanomaterials with advanced optical sensing technology.Micro-nano optical sensors,are easily integrated and realized the intelligent,have advantages such as fast,simple and convenient detection,high sensitivity,small volume and non-destructive measurement,which have opened a new door for the entire sensor field.Therefore,it is of great theoretical value and practical significance to construct and study optical biosensors with micro-nano structures.At present,optical biosensors based on surface plasmon resonance are one of the most widely reported types of micro-nano optical sensors.However,the excitation conditions of these devices are relatively high,and their resolution are generally low.In addition,the measurement stability of micro-nano sensors based on optical fiber technology is difficult to guarantee,and its geometry is not conducive to integration.In response to these problems,based on the advanced optical Tamm states(OTSs),a series of high-performance biosensors based on micro-nano structure are creatively constructed by combining some new micro-nano materials having metal dielectric properties with photonic crystals.The sensing enhancement mechanism of these sensors is systematically studied,and their feasibility and high efficiency are verified by numerical simulation.The content of the paper are completed as follows:1.Firstly,the structure and principle of optical biosensor are introduced.Based on a comprehensive analysis of the performance ofseveral typical micro-nano structure optical sensors and their domestic and foreign development status,one-dimensional photonic crystals based on surface defect is proposed as the most promising sensor model.Then,several new micro-nano materials and their applications in optical biosensors are analyzed.Finally,the main performance parameters of the photonic crystal refractive index sensor are described.2.The structure model of one-dimensional photonic crystal and its electromagnetic theory are studied.Based on the transfer matrix method and the self-consistent theory,the band structure and the transmission properties of one-dimensional photonic crystals are analyzed and verified.Then,the concept of OTSs is expounded,and the forming mechanism and conditions of the Tamm state of one-dimensional photonic crystal based on surface defects are analyzed by taking the structure of metal-distributed Bragg mirror(DBR)as the research object.3.Based on OTSs,a terahertz optical biosensor based on graphene-DBR layered structure was constructed,and the working mechanism and performance of the sensor were analyzed using the improved transfer matrix method.On this basis,in order to obtain the ideal sensing performance,the performance parameters of the sensor have been optimized.4.The optical characteristics of the bulk Dirac semimetal(BDS)in the mid-infrared band are studied.A tunable mid-infrared optical biosensor based on BDS-DBR structure was constructed by combining Al CuFe material with one-dimensional photonic crystal.The simulation results show that this sensor has the characteristics of high sensitivity and ultra-high figure-of-merit.5.Based on the equivalent refractive index method and a variety of fitting algorithms,and taking a mix of water and glycol as the simulationobject,three relationship models of resonance angle(correspond to micro-nano optical sensors based on the structure of Au-DBR,graphene-DBR and BDS-DBR,respectively)and solution concentration are established,which provided a theoretical reference for the practical application of the sensor.Then,the performance of the constructed sensor was compared with the latest reported sensors of the same type,and the results show that the combination of graphene or Dirac semimetal materials and photonic crystals has greatly improved the performances of the sensor.Therefore,we believe that the series of optical sensors will have have great application potential in the field of biological detection.