Optical detection of glucose by means of metal nanoparticles or semiconductor quantum dots

The use of semiconductor QDs or AuNPs for probing the biocatalyzed oxidation of glucose by NAd+ dependent GDH was demonstrated. The study dependent glucose dehydrogenase (GDH) and semiconductor CdSe/ZnS QDs or metallic AuNPs to develop integrated hybrid systems for the optical detection of glucose. The GDH-mediated oxidation of glucose with the constant generation of NADH was also used for the optical detection of glucose by means of AuNPs. The results showed that higher concentrations of NADH, generated upon prolonging the biocatalytic transformation lead to bigger NPs with higher absorbence. Also it was seen that in the absence of glucose or NAD+ or AuNP-GDH, no absorbence changes are observed. The results also revealed that the AuNP seeds associated with GDH act as catalyst for the biocatalytic growth of NPs, suggesting the biosensor application for analyzing low volume body fluids containing limited amount of glucose.