Improved SERS sensitivity on plasmon-free TiO₂ photonic microarray by enhancing light-matter coupling

J Am Chem Soc. 2014 Jul 16;136(28):9886-9. doi: 10.1021/ja5052632. Epub 2014 Jun 30.

Abstract

Highly sensitive surface-enhanced Raman scattering (SERS) detection was achieved on plasmon-free TiO2 photonic artificial microarray, which can be quickly recovered under simulated solar light irradiation and repeatedly used. The sensitive detection performance is attributed to the enhanced matter-light interaction through repeated and multiple light scattering in photonic microarray. Moreover, the SERS sensitivity is unprecedentedly found to be dependent on the different light-coupling performance of microarray with various photonic band gaps, where microarray with band gap center near to laser wavelength shows a lower SERS signal due to depressed light propagation, while those with band gap edges near to laser wavelength show higher sensitivity due to slow light effect.