An amperometric biosensor for the determination of catechol was developed by immobilizing tyrosinase (tyr) on gold nanoparticles (AuNPs) and a (3-mercaptopropyl)-trimethoxysilane (MPTS) sol-gel three-dimensional network film-modified gold electrode. The AuNPs self-assembled in a sol-gel network provided an excellent microenvironment for an enzymatic reaction between tyrosinase and the substrate...

We report on the photoconductive response of nanostructured sol-gel films in function of the silver nitrate concentration (ions and colloids). Silver colloids were obtained by spontaneous reduction process of Ag+ ions to Ag(0). 2-d hexagonal nanosructured sol-gel thin films were prepared by dip-coating method using the non-ionic diblock copolymer Brij58 to produce channels into the film, which ...

This paper presents the optimization process in sol-gel technique to synthesize Titanium dioxide (TiO2) thin films using in-house Nano-TiO2 powder. Nano-TiO2 powder was previously synthesized in our lab from ilmenite which is a tin mining byproduct using a modified hydrothermal method. By varying the mass of Nano-TiO2 powder and acetic acid (catalyst) concentration in the sol-gel process, highl...

This study relates to nanoparticle (NP) platforms that attach to tumor cells externally and only deliver singlet oxygen for photodynamic therapy (PDT) while conserving the embedded photosensitizers (PS). As a model, we demonstrate the successful embedding of the PS meta-tetra(hydroxyphenyl)-chlorin (m-THPC) in NP that are based on a sol-gel silica matrix and also show its positive effect on the...

A novel fiber-optic probe based on reflection-based localized surface plasmon resonance (LSPR) was developed to quantify the concentration of hydrofluoric acid (HF) in aqueous solutions. The LSPR sensor was constructed with a gold nanoparticle-modified PMMA fiber, integrated with a SiO(2) sol-gel coating. This fiber-sensor was utilized to assess the relationship between HF concentration and SiO...

Sol-gel nanoprobes, also known as Photonic Explorer for Bioanalysis with Biologically Localised Embedding (PEBBLE), capable of performing in-vitro intracellular monitoring of reactive oxygen species have been developed using a modified form of 5(6)-carboxyfluorescein diacetate. A sol-gel matrix was selected for the design of the probes as it is photostable, optically transparent and chemically ...

The preparation and applicability of solid phase microextraction (SPME) fibers coated with a sol-gel organically modified silica based on 3-aminopropyltrimethoxysilane and polydimethylsiloxane (APTMS/PDMS) are described here. Micrographs of the coated fibers revealed a rugous surface; the thickness of the coating was estimated to be less than 30 microm. The APTMS/PDMS fibers were tested with sy...

A heat-induced O/W emulsion gel that undergoes a phase transition from sol to gel on heating was formed from the addition of aqueous HCl to a toluene solution of a long-chain amidoamine derivative (C18AA). The heat induced O/W emulsions are highly sensitive to temperature, and the sol-gel transition temperature could be simply controlled by adjusting the C18AA concentration. Interestingly, the ...