Preparation And Study Of SPR Sensor Based On 2D MoS₂

Surface plasmon resonance(SPR)sensor has the characteristics of free biomarkers,real-time rapid detection,and fewer samples,which is different from traditional sensors.It has become a hot spot in the field of optical biosensing research.However,limited by the sensitivity of the sensor,it cannot be directly used to detect some trace biomarkers in human body.Therefore,improving the sensitivity of sensors has become a research hotspot in this field.Modification of SPR sensors with various materials to improve sensitivity is one of the important research directions.2D molybdenum sulfide(MoS2)has excellent photoelectric properties and biological compatibility.Therefore,in this paper,two-dimensional molybdenum sulfide material is used in the preparation of SPR sensor chip and sensitivity improving of SPR sensor.On this basis,the reversible reaction of phenylboric acid and glucose molecules in the hydrogel was introduced to realize the detection of glucose molecules within the range of blood sugar.Finally,the sensor chip is modified with covalent organic skeleton film(Covalent organic frameworks,COF)film to realize the anti-interference of the sensor to protein molecules.The main research contents of this paper are as follows:(1)The SPR sensor chip was designed and prepared based on two-dimensional molybdenum sulfide and sodium chloride(NaCl)solutions,with the weight percentage of 0,5 wt%,10wt%,15 wt%,20 wt%,were detected.The results show that the sensitivity of MoS2-SPR sensor can reach 2205.417 nm/RIU,which is significantly improved compared with that of Au-SPR sensor under the same conditions.(2)Based on the MoS2-SPR sensor platform,a hydrogel film was prepared on the sensor chip.The reversible reaction between phenylboric acid and glucose molecules in the hydrogel was used for detection of glucose molecules in human blood.In this paper,ten kinds of glucose solutions with concentrations ranging from 0 to 33.3 mmol/L were tested.The experimental results show that the hydrogel-MoS 2-SPR sensor has a good response to low concentration of small biological molecules,with the detection limit of 1.1 mmol/L,and can be stably tested in pH=7.4 environment for 1 h.(3)Based on the hydrogel-MoS2-SPR sensor,the COF film is deposited on the sensor chip to realize the anti-interference effect of the sensor on the protein molecules in the blood.The preparation of COF film and the preparation of COF-hydrogel-MoS2-SPR sensing chip are elaborated.Ten glucose solutions at concentrations ranging from 0 mmol/L to 33.3 mmol/L were tested with sensors,and the results were compared with the sensor chip without COF film.The results show that it does not have a large impact on its detection.In response to different protein molecules,50 g/L bovine serum protein(BSA),140 U/L serum amylase(SM),and 4 g/L transferrin(TRF)were tested.Compared with the sensor chip without COF film,it showed anti-interference properties against biological protein molecules in the blood,especially serum amylase and transferrin.