Detection of geosmin using an aptamer-functionalized LSPR chip integrated with a microfluidic platform.

In this paper, we report the development of a localized surface plasmon resonance (LSPR)-based sensor for the detection of geosmin. The LSPR chip was fabricated with 80 nm gold nanoparticles (AuNPs), followed by surface functionalization with a geosmin-specific aptamer. The functionalized chip was integrated into a microfluidic chamber to enable stable and reliable measurements. The fabricated LSPR sensor exhibited a bulk refractive index sensitivity of 85 nm/RIU. Real-time binding studies were performed for geosmin at concentrations of 1, 10, and 50 mg/L. The sensor achieved a limit of detection (LOD) of approximately 0.6 mg/L and showed high selectivity toward geosmin over potential interfering species. These results highlight the potential of the proposed LSPR platform for rapid and selective detection of geosmin. Furthermore, the incorporation of a pre-concentration step is suggested as a feasible strategy to enhance detection sensitivity for practical applications.