Ag-Functionalized Si Nanowire Arrays Aligned Vertically for SERS Detection of Captured Heavy Metal Ions by BSA

A novel surface-enhanced Raman scattering (SERS)-based probe to capture heavy metal ion (Zn2+) by bovine serum albumin (BSA) using Si-nanowire (SiNW) arrays with silver nanoparticles (AgNPs) was developed. layer AgNPs deposited on the SiNW surface RF magnetron sputtering for enhancement of SERS signals. Using a high-resolution transmission electron microscope (HRTEM), observation reveals that AgNP depths 30–75 nm successfully arrays. The Ag peaks in EDS and XRD spectra confirmed presence particles WCA observations showed high affinity Ag–SiNW immobilized BSA (water contact angle (WCA) = 87.1°) ZnSO4 (WCA 8.8°). results FTIR analysis illustrate conjugate bonds exist between zinc sulfate (ZnSO4) –OH groups/–NH groups BSA. resulting SiNWs/Ag NPs composite interfaces large ions detection 0.1 μM. conjugations, illustrating specific sensitivity, which suggests great promise developing label-free biosensors.