Research Of Human IgG Sensor Based On Tilted Fiber Bragg Grating SPR

The concentration of IgG is higher or lower than normal level will bring diseases,the level of IgG concentration is often used as a reference value for immune diseases,so it is significant to detection of human IgG.Now,sensitivity of electrochemical method is low,fluorescence labelling technique will effect molecule activity and Biocore instrument is expensive and large size.In view of above problems,this papr presents a TFBG-SPR sensor coated with grapheme oxide and protein A for detection of different concentrations of human IgG.The sensor has characteristics of small size,high sensitivity and free-label of SPR,high specific surface area and enough fuctional groups of grapheme oxide and orientation for the antibody of protein A.By experimental research,this sensor has realized fast and high sensitivity detection of human IgG.This paper includes following contents:(1)Compare and analyse application of TFBG and TFBG-SPR sensors in sensing field.(2)Analyse basic theory about TFBG and TFBG-SPR.Simulate and optimize structured parameters of TFBG.Research and analyse refractive index and temperature characteristics of TFBG and TFBG-SPR experimentally.(3)Using TFBG biosensor,TFBG and TFBG-SPR biosensor coated with protein A for detection detection of human IgG in the concentration range of 30μg/ml-100μg/ml Experimental results are as follows:for these three sensors,sensitivity is 0.015 dB/(μg/ml),0.037dB/(μg/ml),and 0.054dB/(μg/ml),respectively.By analyzing above results,it can be obtained that after coating with protein A on TFBG surface and Au surface,the sensitivity has been improved 2.3 times and 3.4 times,respectively.It proves that Protein A fixing antibody directional so as to increase the combination efficiency between antigen and antibody,and good biocompatibility of Au film for improving sensitivity.(4)Using TFBG and TFBG-SPR biosensor coating with graphene oxide for measuring concentration of 30μg/ml-100μg/ml human IgG solutions,experimental results are as follows:for these two sensors,sensitivity is 0.044dB/(μg/ml),and 0.039dB/(μg/ml),respectively.By analyzing above results,it can be obtained that coating grapheme oxide on TFBG surface and Au surface,sensitivity has increased 1.9times and 2.5times,respectively.It improves that high specific surface area and enough functional group of grapheme oxide adsorbs more antibodies to improve sensitivity.(5)Based on above conclusions:TFBG-SPR biosensor coated with graphene oxide and protein A has been presented.This sensor has characteristes of high sensitivity and free-label of SPR,adsorbing more antibody of graphene oxide and fix antibody directional of protein A.By measuring 30μg/ml-100μg/ml concentration human IgG solutions,experimental results are as follows:sensitivity is 0.096dB/(μg/ml),lowest detectable limit is 1μg/ml.By analyzing above results,it can be obtained that sensitivity has increased 6 times than TFBG sensor,and it proves the affects of SPR,graphene oxide and protein A for improving sensitivity.TFBG-SPR biosensor coating with graphene oxide and protein A has been designed.By experimental research,it has realized measurement of human IgG solution with different concentration,and provides a solving idea for detection of low concentration of biological samples.