title: The inhibition of fluorescence resonance energy transfer between quantum dots for glucose assay.
abstract: Fluorescence resonance energy transfer (FRET) between two quantum dots of different sizes causes fluorescence quenching. Hereby a binding site pre-blocking approach is proposed to avoid this effect. Pre-binding of glucose on the donor occupies the binding sites and thus blocks resonance energy transfer between the two quantum dots, protecting the fluorescence from being quenched. A glucose assay is developed based on this approach. The glucose content is correlated with the fluorescence difference in the absence and in the presence of glucose. In practice, Green QDs-Con A conjugates are used as donors and Red QDs-NH(2)-glu conjugates as acceptors to form FRET system. The inhibition of fluorescence quenching is then measured in the presence of glucose. A linear calibration graph is achieved within 0.1-2.0 mmolL(-1), along with a detection limit of 0.03 mmolL(-1) and a RSD of 2.1% (1.0 mmolL(-1)). 91-105% of glucose in serum and urine samples is recovered. It is worth mentioning that the present glucose assay approach also generates a fluorescence chromatic difference imaging, and the color display clearly identifies the glucose contents by visual detection with a distinguishing ability of ca. 0.5 mmolL(-1). The present approach can potentially be used for the clinical determination of glucose in biological samples which can be further developed into a glucose sensor.
authors.affiliation: Research Center for Analytical Sciences, Northeastern University, Box 332, Shenyang 110819, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.forename: Li-Pei
authors.initials: LP
authors.lastname: Zhang
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Chen
authors.forename: Ming-Li
authors.initials: ML
authors.lastname: Chen
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Wang
mesh_terms: D001786:Blood Glucose / Q000032:analysis*; D002138:Calibration; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D006029:Glycosuria / Q000652:urine*; D006801:Humans; D057230:Limit of Detection; D045663:Quantum Dots
chemical_list: D001786:Blood Glucose