Recycling of surface-enhanced Raman substrates by ultraviolet cleaning

Commercial substrates used for surface-enhanced Raman spectroscopy (SERS) are investigated for their reusability following cleaning with 254-nm UV light from a mercury lamp. SERS of Rhodamine 6G (Rh6G, a dye) and RDX (an explosive) is investigated. It is found that without UV irradiation, the substrate is usable only once, since it is not possible to dislodge the analyte either by prolonged immersion in distilled water or by ultrasonic cleaning. However, prolonged exposure to 254-nm UV followed by immersion in distilled water removes most of the analyte, making the substrate reusable for new SERS measurements. The technique of UV cleaning is demonstrated by recycling the same substrate several times and comparing SERS spectra taken after each cleaning cycle. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3491201]