Biosensors and Bioelectronics 2015-12-15

Multi-positively charged dendrimeric nanoparticles induced fluorescence quenching of graphene quantum dots for heparin and chondroitin sulfate detection.

Yan Li, Hongcheng Sun, Fanping Shi, Nan Cai, Lehui Lu, Xingguang Su

文献索引：Biosens. Bioelectron. 74 , 284-90, (2015)

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摘要

A label-free fluorescence assay for rapid and sensitive detection of heparin (Hep) or chondroitin sulfate (CS) was developed by guanidine-terminated poly (amidoanime) (PAMAM-Gu(+)) dendrimers induced aggregation of graphene quantum dots (GQDs). The fluorescence of GQDs was obviously quenched after mixing with PAMAM-Gu(+). However, the addition of highly negatively charged Hep or CS into the fluorescence sensing system resulted in the fluorescence recovery. Because the multi-positively charged PAMAM-Gu(+) would prefer to bind with highly negatively charged Hep or CS, resulting in the deaggregation of GQDs. Under the optimized experimental conditions, the recovery of fluorescence intensity ratio I/I0 (I0 and I were the fluorescence intensity of the sensing system in the absence or presence of target analytes, respectively) was proportional to the concentration of target analytes in the range of 0.04-1.6 μg mL(-1) for Hep and 0.1-2.5 μg mL(-1) for CS. In addition, this method afforded high sensitivity with the detection limit as low as 0.02 μg mL(-1) and 0.05 μg mL(-1) for Hep and CS, respectively. All results suggested that the fluorescence turn-on method could be successfully employed for sensitive and selective detection of heparin analogs.Copyright © 2015 Elsevier B.V. All rights reserved.