Silver island deposited titanium oxide composite substrate for surface-enhanced Raman spectroscopy with high enhance factor and ultra low detection concentration

Silver island deposited titanium oxide composite substrates for surface-enhanced Raman spectroscopy (SERS) have been synthesized by successively growth of titanium oxide on glass substrate and in situ deposition of silver islands. The underlying titanium oxide film is porous in structure with an uniform thickness of about 100 nm, and the silver particles are deposited both as flower-like islands and small nanoparticles with a size of 2-3 nm on the TiO2. The silver island deposited titanium oxide composite substrates show excellent SERS performance. The detection concentration for 4-aminothiophenol (PATP) is measured to be as low as 10−10 M, while the enhance factor reaches to 108∼9, which demonstrate the good SERS properties of the silver island deposited titanium oxide composite substrates and their great potential for molecular detection.