Surface-enhanced Raman scattering sensor for quantitative detection of trace Pb2+ in water

A method for sensing trace lead ion (Pb 2+ ) in water based on an ultrasensitive surface-enhanced Raman scattering sensor is developed. Silicon nanowire arrays were first grown, followed by the deposition of gold nanoparticles on the surface to form Au@SiNWAs substrate with an enhanced factor of ∼5.96 × 10 5 . Au@SiNWAs was modified with crystal violet, and the lowest detectable concentration of Pb 2+ was about 10 −13 M level. There was no obvious interference when other metal ions were present, demonstrating the excellent selectivity for Pb 2+ . The sensor is simple to prepare, and can be used repeatedly.