Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167, Iran.
Chemistry Department, College of Science, University of Raparin, Rania, Kurdistan Region, Iraq.
Food Chem. 2019 Oct 15;295:530-536. doi: 10.1016/j.foodchem.2019.05.169. Epub 2019 May 24.
In this work, new detection route for ascorbic acid was designed. First, highly luminescent sulfur and nitrogen doped graphene quantum dots (S,N-GQDs) were prepared via simple hydrothermal method using citric acid and thiourea as the C, N and S sources respectively. The prepared S,N-GQDs are characterized by XRD, HRTEM, FTIR, EDS and PL. Investigations showed that prepared S,N-GQDs have a good photostability and excitation-dependent emission fluorescence. Prepared S,N-GQDs showed maximum excitation wavelength and emission wavelength at 400 and 462 nm, respectively. In the following, prepared S,N-GQDs were applied as a photoluminescence probe for detection of ascorbic acid (AA). The designed sensor was based on "off-on" detection mode. The developed sensor had a linear response to AA over a concentration range of 10-500 μM with a detection limit of 1.2 μM. The regression equation is Y = 0.0014 X + 1.2036, where Y and X denote the fluorescence peak intensity and AA concentration, respectively.
在这项工作中，设计了一种新的抗坏血酸检测途径。首先，通过简单的水热法，分别以柠檬酸和硫脲为碳、氮和硫源，制备了具有高光致发光性能的硫、氮掺杂石墨烯量子点（S,N-GQDs）。所制备的 S,N-GQDs 通过 XRD、HRTEM、FTIR、EDS 和 PL 进行了表征。研究表明，所制备的 S,N-GQDs 具有良好的光稳定性和激发依赖性发射荧光。所制备的 S,N-GQDs 的最大激发波长和发射波长分别为 400nm 和 462nm。随后，将制备的 S,N-GQDs 用作检测抗坏血酸（AA）的光致发光探针。所设计的传感器基于“关-开”检测模式。该传感器对 AA 的浓度范围在 10-500μM 内具有线性响应，检测限为 1.2μM。回归方程为 Y=0.0014X+1.2036，其中 Y 和 X 分别表示荧光峰强度和 AA 浓度。
