Silver-doped sol-gel films as the substrate for surface-enhanced Raman scattering

Abstract

A method was developed to prepare silver-doped sol-gel Ðlms for surface-enhanced Raman scattering (SERS) detection. The technique involves Ðrst doping silver ions as a silver ammine complex into a sol-gel [ Ag(NH 3 ) 2 ' ] matrix, followed by chemical reduction of the doped silver ions into the corresponding silver metal particles. The silver-doped sol-gel Ðlms coated on a glass substrate exhibit strong enhancement (24 000-fold) of Raman scattering from molecules adsorbed on the surface. Very stable SERS spectra of benzoic acid over a period of 48 h were obtained with the new silver substrate.

Silver nanoparticle-treated filter paper as a highly sensitive surface-enhanced Raman scattering (SERS) substrate for detection of tyrosine in aqueous solution

“…A wide range of methods have been developed to prepare nanometer-scale particles for SERS applications. For instance, SERS substrates can be prepared by electrochemically roughening electrodes [8,9], metal colloids [10][11][12][13], island films prepared by vapor deposition [14], silver-doped sol-gel films [15][16][17][18], and silver-mirror (Tollen's) reaction [19][20][21][22][23][24]. Among these methods, the silver-mirror reaction offers several advantages such as low cost, no need for delicate equipment, and virtually no limitations on substrate materials.…”

Improving the analytical figures of merit of SERS for the analysis of model environmental pollutants

“…Considerable work has been done in the area of substrate design. Among the approaches are silver islands on glass, 19 colloidal silver solutions, 20 colloidal particles encapsulated in sol-gels, 21 silver-coated microspheres, 22 metallized polymers 23 and more regular structures such as those created by nanosphere lithography. 24 The inhomogeneous adsorption of the analyte on traditional SERS substrates, such as colloidal silver and silver-island films, in combination with their susceptibility to oxidation upon contact with water and other oxidizing agents, are among the variables that contribute to these poor figures of merit.…”

Detection of 4′,6-diamidino-2-phenylindole within silver-doped silica sol- and aerogels using surface-enhanced Raman spectroscopy

“…Modified silica sol-gels and xerogels have been shown to be capable of functioning as substrates for SERS measurements, especially those that incorporate noble metal nanoparticles [12][13][14][15]. Sol-gel chemistry can be used to stabilize nanoparticles and decrease agglomeration by encapsulating the nanoparticles in a silica host matrix.…”

“…Previous studies have shown that the sol-gel forms a continuous mesoporous network throughout the material. The pores can then collapse during conventional drying to form a xerogel [4,12] or be preserved by supercritical drying to form an aerogel [16][17][18][19]. Despite the published work regarding the use of modified xerogels as SERS substrates, there is little reported use of modified aerogels as SERS substrates.…”