A novel optical nanoprobe for sugar sensing is reported. The assay used an electrospun polyamide mesh containing Au salts. The reaction of carbohydrates with these Au salts in alkaline media generates gold nanoparticles (AuNPs) at room temperature without the need for Au seeds.
Food rich in antioxidant such as green tea was identified by their reactions on gold-nanoparticles changing it to coloured colloidals. Reactions were probed on few nanomoles of gold salt. This was based on nylon nanofibrous substrates produced by electrospinning and doped with gold ions. The total reducing sugar content of the samples were analyzed by intensity of colour change of gold-particles that varied with the sugar. The strongest purple coloration happened with galactose, followed by glucose, then fructose, whilst the non-reducing sugar sucrose showed no change!
Scampicchio et al, Optical nanoprobes based on gold nanoparticles for sugar sensing, 2009 Nanotechnology 20 135501 doi:10.1088/0957-4484/20/13/135501