CdSeTe quantum dot based fluorescence sensor systems for detection of vitamin C, folic acid and glucose

The levels of metabolites in the human body provide significant clues for the diagnosis, staging, and therapy planning of diseases. Recently, fluorescence-based metabolite detection methods have become popular thanks to their important advantages such as using less sample, not requiring prior preparation, and responding quickly. In this regard, quantum dots (QDs) are unique materials in metabolite detection studies due to their well-known fluorescence-emitting structures, high luminescence, tunable size, and high absorption cross-section ratio. In this experiment, we synthesized the mercaptopropionic acid (MPA) capped CdSeTe-alloy QDs and investigated their metabolite detection performance using vitamin C (VitC), folic acid (FA) and glucose (Glu). Under the optimized conditions (pH, QD concentration and incubation times), the quenching fluorescent responses were obtained from metabolite-added CdSeTe QD solution which ascribed to the Forster resonance energy transfer (FRET) mechanism. The linearity ranges and limit of detection (LOD) values for VitC, FA and Glu were determined. The presented method has also been applied to quantify the amount of metabolites in human blood serum samples in the linear ranges of 10-20 mu g/mL for CVit, 7.5-20 ng/mL for FA, and 0.25-1.5 mg/mL for glucose, with an accuracy of over 95 %. This sensor system has also shown a noteworthy advantage regarding sensitive, selective, reliable and cost-effective metabolite detection technique.