Silver deposited polystyrene (PS) microspheres for surface-enhanced Raman spectroscopic-encoding and rapid label-free detection of melamine in milk powder

Silver nanoparticles coated amino polystyrene microsphere (PS-NH2/Ag NPs) substrates with uniform morphology and high SERS activity were synthesized using novel controlled deposition method. The promising application of this kind of PS-NH2/Ag NPs substrates for nondestructive detection, SERS encoding and ultrasensitive detection of melamine in milk powder was explored.