In situ formation of silvernanostructures within a polysaccharide film and application as a potential biocompatible fluorescence sensing medium

Abstract

Simple to manufacture polysaccharide films containing a silver salt, from which silver nanostructures can be produced in situ by light irradiation, were investigated for possible biosensing applications. The silver nanostructures were patterned in situ within a film and cast from a liquid solution of gellan gum, using a compact time-resolved fluorescence microscope. The position and time of irradiation, made using a semiconductor laser in CW mode, were computer controlled. Evidence for their formation was obtained via UV-vis spectroscopy, AFM and SEM-EDAX. On drying the polysaccharide film exhibited a viscosity increase of several orders of magnitude, which was elucidated by changes in the fluorescence lifetime of a probe molecule (DASPMI). To demonstrate the potential for biocompatible sensing applications the influence of the presence of areas of silver nanostructures on the fluorescence of a protein (bovine serum albumin) labelled with fluorescein isothiocyanate was monitored via fluorescence lifetime imaging and the photophysical behaviour found to be consistent with a metal induced increase in the radiative decay rate.

Tree gum-based renewable materials: Sustainable applications in nanotechnology, biomedical and environmental fields

“…Functional properties (Food applications) Non-food applications of gum derivatives and composites silver nanoparticle dispersions and hydrogels (Dhar et al, 2012) biosensing (Hungerford et al, 2012) Gum arabic (GA)…”

A 192×128 Time Correlated Single Photon Counting Imager in 40nm CMOS Technology

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