Introduction. One of the main areas of application of SPR sensors is biochemical analysis. The "Plasmontest" device, developed at the Institute of Cybernetics of the National Academy of Sciences of Ukraine, was used for rapid diagnosis of various concentrations of the tumor marker spermine. Colloidal gold nanoparticles stabilized by sodium citrate were used as a sensitive layer for the detection of biogenic polyamines as markers of prostate cancer development. Two methods of conducting an experiment on spermine detection using colloidal gold nanoparticles are proposed. The purpose of the paper is to show the possibility of detecting the tumor marker spermine in different concentrations using the "Plasmontest" device. To solve this problem it is necessary to provide a series of experiments on the application of colloidal gold solutions with different methods of deposition of reagents. The results. With the help of the "Plasmontest" software and technical complex, a series of biochemical experiments were carried out using solutions of spermine in the concentration range of 50 nM - 500 nM and colloidal gold in a concentration of 3·10-4 M. Two methods of applying reagents were proposed: spermine – colloidal gold and colloidal gold – spermine. Both techniques made it possible to observe a shift in the SPR angle, which means the adsorption of spermine on the surface of a gold film with colloidal gold nanoparticles. Conclusions. It is shown that the developed software and technical complex "Plasmontest" allows monitoring the course of biochemical reactions at low concentrations of the investigated reagents. Studies of the possibility of detecting spermine in different concentrations in the presence of gold nanoparticles using the PPR method open the prospect of creating a biosensor for spermine. Keywords: surface plasmon resonance, biosensor, nanoparticles, spermine.
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