Quantum dots-based label-free fluorescence sensor for sensitive and non-enzymatic detection of caffeic acid.

Xia Xiang, Jianbin Shi, Fenghong Huang, Mingming Zheng, Qianchun Deng

Index: Talanta 141 , 182-7, (2015)

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Abstract

We have developed a label-free fluorescence sensor for caffeic acid (CA) by the use of CdTe:Zn(2+) quantum dots (CdTe:Zn(2+) QDs) as an output signal. The principle of sensor is based on the fluorescence quenching and binding properties of Fe(2+) toward QDs and CA, respectively. To provide a fluorescence turn-on mode for CA detection, Fe(2+) is first mixed with QDs solution, leading to a low fluorescence emission. With the addition of CA, the fluorescence of QDs is recovered due to the strong binding interaction between CA and Fe(2+). Thus, a QDs-based label-free fluorescence sensor, designed in a simple mix-and-detect format, is established for CA detection. This study demonstrated here not only offers simple, sensitive and non-enzymatic detection method for CA, but also brings to light a new application of QDs in the food analysis. Copyright © 2015 Elsevier B.V. All rights reserved.