title: Microfluidic setup for on-line SERS monitoring using laser induced nanoparticle spots as SERS active substrate.
abstract: A microfluidic setup which enables on-line monitoring of residues of malachite green (MG) using surface-enhanced Raman scattering (SERS) is reported. The SERS active substrate was prepared via laser induced synthesis of silver or gold nanoparticles spot on the bottom of a 200 μm inner dimension glass capillary, by focusing the laser beam during a continuous flow of a mixture of silver nitrate or gold chloride and sodium citrate. The described microfluidic setup enables within a few minutes the monitoring of several processes: the synthesis of the SERS active spot, MG adsorption to the metal surface, detection of the analyte when saturation of the SERS signal is reached, and finally, the desorption of MG from the spot. Moreover, after MG complete desorption, the regeneration of the SERS active spot was achieved. The detection of MG was possible down to 10-7M concentration with a good reproducibility when using silver or gold spots as SERS substrate.
authors.affiliation: Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz, Germany.
authors.forename: Oana-M
authors.initials: OM
authors.lastname: Buja
authors.affiliation: Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz, Germany.
authors.forename: Ovidiu D
authors.initials: OD
authors.lastname: Gordan
authors.affiliation: Faculty of Physics, Babes-Bolyai University, Kogalniceanu 1, 400084 Cluj-Napoca, Romania; MEDFUTURE - Research Center for Advanced Medicine, Iuliu Hatieganu University of Medicine and Pharmacy, Louis Pasteur 4-6, 400349 Cluj-Napoca, Romania.
authors.forename: Nicolae
authors.initials: N
authors.lastname: Leopold
authors.affiliation: Fraunhofer Institute for Electronic Nano Systems, Technologie-Campus 3, 09126 Chemnitz, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Morschhauser
authors.affiliation: Fraunhofer Institute for Electronic Nano Systems, Technologie-Campus 3, 09126 Chemnitz, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Nestler
authors.affiliation: Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz, Germany.
authors.forename: Dietrich R T
authors.initials: DR
authors.lastname: Zahn
keywords: SERS; gold nanoparticles; malachite green; microfluidic setup; silver nanoparticles