Zhang Junyu, Chen Yi, He Yiyang, Bai Yiwen, Wang Wei, Yang Guangxin, Kong Cong, Cao Xiao, Gu Lin
School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, P. R. China.
School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province, 710049, China.
Anal Methods. 2024 Nov 7;16(43):7413-7423. doi: 10.1039/d4ay01539h.
A green and eco-friendly solvothermal approach is proposed for the synthesis of carbon quantum dots (CQDs) from watermelon rind. The as-prepared CQDs exhibited superior teal fluorescence in aqueous solutions, with a quantum yield of 13.9%. The CQDs and rhodamine B (RhB) were demonstrated to selectively react with Fe and Cu, leading to a fluorescence (FL) quenching effect, which was successfully used for constructing "double-response-off" type ratiometric FL probes. A comparative study was conducted to assess the sensitivity and accuracy of ratiometric fluorescent probes, specifically those based on CQDs alone and in combination with RhB, for the selective detection of Fe and Cu. By plotting the ratio of the differential fluorescence (Δ) signals of CQDs to that of RhB against the practical application analyte concentration, the detection limits for Fe (1.75 μM) and Cu (0.43 μM) were markedly improved. The quenching mechanism was further explored, and the detection of Fe and Cu in surface water was demonstrated, showcasing the potential of efficient and effective nanosensors based on a static quenching effect. Futhermore, the addition of ascorbic acid can restore the fluorescence quenched by Fe. Therefore, in the presence of copper and iron, the ratiometric probe can demonstrate the ability to identify two different metals.
本文提出了一种绿色环保的溶剂热法，用于从西瓜皮中合成碳量子点（CQD）。所制备的CQD在水溶液中表现出优异的蓝绿色荧光，量子产率为13.9%。实验证明，CQD和罗丹明B（RhB）能与铁和铜发生选择性反应，产生荧光猝灭效应，该效应成功用于构建“双响应关闭”型比率荧光探针。开展了一项对比研究，以评估比率荧光探针（特别是基于单独的CQD以及CQD与RhB组合的探针）对铁和铜的选择性检测的灵敏度和准确性。通过绘制CQD与RhB的差分荧光（Δ）信号之比相对于实际应用分析物浓度的曲线，铁（1.75 μM）和铜（0.43 μM）的检测限得到显著提高。进一步探究了猝灭机制，并展示了在地表水中对铁和铜的检测，凸显了基于静态猝灭效应的高效纳米传感器的潜力。此外，添加抗坏血酸可以恢复被铁猝灭的荧光。因此，在存在铜和铁的情况下，比率探针能够展现出识别两种不同金属 的能力。
