Interaction potential surface between Raman scattering enhancing nanoparticles conjugated with a functional copolymer.

A novel Raman scattering enhancement was discovered using colloid nanoparticles conjugated with an amine-based copolymer. The interaction potential surface between Raman scattering enhancing nanoparticles was clarified by combining a small-angle scattering method and a model-potential-free liquid-state theory as an in situ observation in the solution state. The potential surface indicates that the most stable position is located around 0.

Colorimetric assay of glutathione based on the spontaneous disassembly of aggregated gold nanocomposites conjugated with water-soluble polymer.

This article describes the glutathione-triggered disassembly of gold nanocomposites composed of gold cores and water-soluble copolymers [poly(N-n-isopropylacrylamide-co-acryloyldiethyletriamine)] attached to the surfaces of gold cores. The gold nanocomposites exhibit a bluish purple color because of the assembled gold cores that are conjugated with the diethylenetriamine groups incorporated into the copolymers. Glutathione added to the gold nanocomposite solution adsorbs onto the surface of the gold cores to liberate diethylenetriamine groups, resulting in spontaneous disassembly that changes the color of the solution to a reddish shade.

Blue-to-red chromatic sensor composed of gold nanoparticles conjugated with thermoresponsive copolymer for Thiol sensing.

We describe the first determination of thiol compounds with gold nanocomposites composed of gold nanoparticles and thermoresponsive copolymers having polyamino groups. The gold nanocomposites, which are used as a chromatic sensor, reveal chromatic change from blue to red with thermal stimuli, heating followed by cooling the solution. The blue-to-red chromatic change results from disassembly of the gold nanocomposites, which arises from shrinkage of the thermoresponsive copolymers bound to the gold nanoparticle surfaces due to the phase transition induced by thermal stimuli.