Improved Design Of SPRi Sensor And Research On Microbiological Detection Technology

Surface plasmon resonance(SPR)has been developing rapidly towards the directions of high throughput,high sensitivity,high spatial resolution and multi-function,and its application area has been widened continuously over the past 30 years.Among them,surface plasmon resonance imaging(SPRi)has become a hotspot in recent years due to its high throughput,and the requirements of SPRi are becoming more and more demanding in relative fields.In addition,because of their big number and fast variation,microorganisms,including influenza viruses and bacteria,are affecting the normal life of mankind.Therefore,it is of great significance to improve the performance of SPRi sensor and apply it to microbiological detection.The main research contents and achievements of this project include:(1)Firstly,the basic principle of polarization control light intensity modulated SPRi sensor was analyzed.Then the optical parameters and their errors of the traditional gold film extinction method with pure water were studied and simulated.Thirdly,the SPRi sensor system was constructed and its performance was tested.The detection limit of NaCl solution is 50-100 mg/L.(2)A method of optimizing the extinction index,ie,improving the sensitivity near the refractive index of the pure water by changing the extinction index,is proposed,breaking the idea of real liquid extinction.Based on this method,the SPRi sensor was constructed and its performance was tested.The refractive index resolution is 1.35 × 10-6 RIU.The detection limits are 0.025 g/L NaCl solution and the BSA antibody solution with 51200 times dilution.This method is of high practicability and realizes the high sensitive detection of SPRi sensor for trace aqueous solution samples.(3)Three data processing methods of zero-phase-shift digital filter,wavelet analysis and Hibert-Huang transform(HHT)and their applications in SPRi sensor refractive index sample and biological sample detection experiments were studied.HHT has the characteristic of self-adaptability,which can generate the corresponding basis functions for different experimental data without changing any parameters.It is easy to operate,and can obtain the ideal filtering result,thus improving the performance of the sensor.(4)High-throughput online culture,real-time detection of Escherichia coli experiment based on SPRi was conducted.Two kinds of microcavities,0.5 ?L and 1.5 ?L,were experimented respectively.The results showed that the smaller the volume of the droplet,the faster the growth rate of the bacterial growth.With 0.5 ?L microcavity,105 CFU/mL Escherichia coli can be detected in 10 h.It is expected to solve the problems such as long time,complicated operation and expensive probe of bacteria detection in some fields including food safety.(5)Utilizing the channel SPR sensor with angular interrogation developed by our research group,two detection experiments of H7N9 subtype influenza virus were carried out based on the antigen-antibody recognition system and the base complementary recognition system respectively.The two methods both can be used to detect the H7 subtype of influenza virus,which is simple,rapid and low cost.They can be used as a supplement to the identification and detection methods of influenza virus.