Carbon Dots Derived from the Maillard Reaction for pH Sensors and Cr (VI) Detection
Zhi Ma, Yun Ma, Meiyu Gu, Xiyue Huo, Sainan Ma, Yini Lu, Ning Yao, Xuan Zhang, Bo Tian, Zhibiao Feng
Abstract
The Maillard reaction involves a series of complex reactions; fluorescent compounds have been considered as vital intermediate products of the reaction. In this article, carbon dots (CDs) based on the Maillard reaction (MR-CDs) were prepared with L-tryptophan and D-glucose, and they had excellent photoluminescence stability. MR-CDs showed stable pH-dependence behavior and exhibited an excellent linear response to pH in the range of 4.0-7.5 and 7.5-13.0, respectively. Under the masking effect of sodium fluoride for Fe(III), MR-CDs showed excellent selectivity and sensitivity for Cr (VI). The linear range of Cr(VI) was 0.2-50 μM and the limit of detection was 20 nM. (S/N ≥ 3). Furthermore, MR-CDs were used to detect Cr(VI) in tap water samples. The recoveries were between 95.8% and 98.94%, and RSDs were less than 3.17%.