Lysozyme-Imprinted Surface Plasmon Resonance Chips Decorated with Gold Nanoparticles for Lysozyme Detection

In this study, lysozyme-imprinted (Lyz-AuNP-MIP) and nonimprinted (AuNP-NIP) surface plasmon resonance (SPR) sensors modified with gold nanoparticles (AuNPs) were prepared for signal amplification and real-time determination of lysozymes from both aqueous lysozymes and artificial plasma, artificial urine, and artificial tear solutions. Furthermore, lysozyme-imprinted (Lyz-MIP) SPR sensors without AuNPs were prepared to study the signal enhancing effect of the AuNPs. The surface morphology of all prepared SPR sensors was characterized by atomic force microscopy and contact angle measurements. After the characterization study, kinetic studies were carried out using lysozyme solutions (pH 7.4 phosphate buffer), artificial plasma, artificial urine, and artificial tear prepared from 0.01-500 μg/mL concentrations using Lyz-AuNP-MIP SPR sensors for lysozyme determination. Using the kinetic analysis data obtained from the Lyz-AuNP-MIP SPR sensors, the limit of detection and limit of quantification were 0.008 and 0.026 μg/mL, respectively. Competitive agents, such as myoglobin and hemoglobin, were used to demonstrate the selectivity of Lyz-AuNP-MIP and AuNP-NIP SPR sensors. Furthermore, after optimizing the experimental studies for lysozyme determination, lysozyme determination was also performed in artificial plasma, artificial urine, and artificial tear solutions, and the recoveries were calculated to be approximately 99%.