【摘要】 本研究成功制备了发射蓝光的石墨烯量子点（graphene quantum dots, GQDs）和发射橙光的邻苯二胺量子点（O-phenylenediamine quantum dots, O-CDs）。实验结果表明，Mg²⁺对O-CDs的荧光强度具有显著的淬灭效应，导致其在565 nm处的荧光发射强度降低。与此同时，GQDs对Mg²⁺的响应相对迟钝，在435 nm处的荧光发射强度保持稳定。基于此，通过计算体系的荧光强度比值(I₅₆₅/I₄₃₅),可实现水中Mg²⁺质量浓度的定量测定，检出限达到2.95μg/L。在0～20.0μg/L和20.0～200.0μg/L范围内，I₅₆₅/I₄₃₅与Mg²⁺质量浓度分别呈良好的线性关系，且在实际水样中Mg²⁺的加标回收率在96.7%～103.6%。更多还原

【Abstract】 In this study, we successfully synthesized blue-emitting graphene quantum dots（GQDs） and orange-emitting o-phenylenediamine quantum dots（O-CDs）. Experimental results showed that the fluorescence intensity of O-CDs was significantly quenched by Mg²⁺, leading to a marked decrease in the emission intensity at 565 nm. In contrast, the fluorescence intensity of GQDs at 435 nm remained nearly unchanged in the presence of Mg²⁺. By calculating the fluorescence intensity ratio(I₅₆₅/I₄₃₅), we could accurately and quantitatively determine the concentration of Mg²⁺ in water, with a detection limit as low as 2.95 μg/L. The method demonstrated excellent linear correlations between I₅₆₅/I₄₃₅ and Mg²⁺ concentration in the ranges of 0-20.0 μg/L and 20.0-200.0 μg/L, respectively. Moreover, the spiked recoveries of Mg²⁺ in real-world water samples ranged from 96.7% to 103.6%.更多还原