Quantum dots (QDs) have attracted extensive attention in biomedical applications， because of their broad excitation spectra, narrow and symmetric emission peaks etc. Furthermore, near-infrared (NIR) QDs have further advantages including low autofluorescence, good tissue penetration and low phototoxicity. In this work, the electrostatic interaction and fluorescence resonance energy transfer (FRET) between NIR CdTe/CdS QDs and cationic conjugated polymer (CCP) was studied for the first time. Based on the newly discovered phenomena and the result that hydrogen peroxide (H2O2) can efficiently quench the fluorescence of NIR CdTe/CdS QDs, a novel NIR ratiometric fluorescent probe for determination of H2O2 and glucose was developed. Under the optimized conditions, the detection limit of H2O2 and glucose assay were 0.1mM and 0.05mM (S/N=3), with a linear range of 0.2-4mM and 0.1-5mM, respectively. Because of the NIR spectrum, this ratiometric probe can be also applied for the determination of glucose in whole blood samples directly, providing a valuable platform for glucose sensing in clinic diagnostic and drug screening.
Keywords: Cationic conjugates polymers; Fluorescence resonance energy transfer; Near-infrared quantum dots; Ratiometric; Whole blood glucose.
Copyright © 2017. Published by Elsevier B.V.