Highly selective colorimetric onsite sensor for Co²⁺ ion detection by povidone capped silver nanoparticles

Highly efficient colorimetric povidone (PVP) mediated Ag nanosensing strategy has been adopted for the sensitive and selective quantification of cobalt ion in aqueous system. PVP functionalized Ag nanoparticles grown by chemo-reductive methodology at ambient conditions. These efficient nanoparticles were confirmed by UV–Vis (UV–Vis) spectroscopic characteristic absorption peak at 390 nm and strong Fourier Transform Infrared (FT-IR) stretching bend at 455 cm⁻¹. The topographical and crystalinity analysis by Field Emission Scanning Electron Microscope (FESEM) and X-ray diffractometer (XRD) analysis reveals that the obtained PVP@Ag NPs have rough surface and size in range of 30–45 nm respectively. Later PVP@Ag NPs were employed to develop a highly selective and sensitive colorimetric nanosensor for Co²⁺ detection in the concentration from 0.1 to 5 μM in aqueous environment.