Detection Of C-Reactive Protein And Its Kinetic Constants Based On Surface Plasmon Resonance

Surface plasmon resonance（SPR）sensors have the advantages of label-free,high-throughput,pollution-free,unaffected by background,real-time detection,samples without purification,and high sensitivity.They are widely used in biomedical detection,drug analysis,food safety and environmental testing.Ho wever,traditional SPR equipment requires large-volume and expensive instrument,such as spectrometer,and also requires specialized personnel to operate,which makes the cost expensive.In this paper,a grating-type coupled SPR sensing system is made by periodically fabricate nanocup arrays over a large area by using nanoimprinting methods.The surface plasmon polaron is excited,and the"extraordinary optical transmission"phenomenon is generated through the nanopore at a specific resonance wavelength to realize SPR sensing.In this paper,the concepts and theories of CRP and SPR sensors are briefly introduced first,and various methods for quantifying CRP are summarized.In this paper,the following three different detection methods are designed to detect the concentration of CRP:1.Design a label-free SPR biosensor based on a 96-well plate to dynamically measure the binding kinetics of CRP and CRP antibodies.The double-antibody sandwich method can increase sensitivity and enhance specificity.The sensor reached a limit of detection（LOD）of 50 ng/m L CRP.The value of binding rate constant,the dissociation rate constant the dissociation equilibrium is 3.11×10⁶（±0.40×10⁶）M^-1s^-1,2.00×10^-2(±0.26×10^-2)s^-1and 6.44×10^-9(±0.38×10^-9),respectively.2.An ultra-sensitive SPR enhanced immunoassay method is designed.This method can quantify CRP only using CRP antibody and PEG-6000.This method does not require any surface modification and expensive equipment,making it widely applicable to hospitals and laboratories.SPRIT detection of CRP reached a LOD of1ng/m L,which is at least 3 orders of magnitude lower than commonly used immunoassay methods and CRP concentration in plasma.3.An ultra-sensitive SPR colorimetric biosensor is designed.This method quantifies CRP by continuously taking pictures under a common white light source and a microscope.The changes in the gray value of the red channel are analyzed by using software Image J.The SPR colorimetric method can reach a LOD of 5ng/m L CRP,and successfully distinguished 1ng/m L CRP and negative control in artificial saliva.This method detects CRP non-invasively and brings good news to patients who need to monitor CRP multiple times in a row.