SPR Signal Enhancement With Silver Nanoparticle-Assisted Plasmonic Sensor for Selective Adenosine Detection

In this study, we fabricated adenosine imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-L-cysteine methyl ester-silver nanoparticles (AgNPs)-N-methacryloyl-L-phenylalanine methyl ester) (MIP-Ag) sensor. It is a sensitive, simple, low-cost, and label-free adenosine determination in an aqueous solution without the need for any complicated coupling processes. The sensor without the addition of AgNPs (MIP) was prepared for control experiments to examine the effect of incorporated AgNPs to increase the signal response of surface plasmon resonance. Also, non-imprinted (NIP-Ag) sensor were designed using the same polymerization recipe without adding adenosine to evaluate the imprinting efficiency. The characterization studies of MIP-Ag, NIP-Ag and MIP sensors were carried out by atomic force microscopy and contact angle measurements. It was determined that the MIP-Ag sensor detected the target adenosine molecule 5.10 times more selectively than the competitor guanosine and 3.92 times more than thymidine. Imprinting efficiency was determined by comparing the signal response of MIP-Ag and NIP-Ag sensors. Repeatability studies of the MIP-Ag sensor were statistically analyzed for the 1.0 ppm adenosine, and the percent relative standard deviation of the intraday assays of less than 1.0% showed an insignificant decrease in the detection of adenosine after four adsorption-desorption cycles.