Abstract：
Most known chemiluminescence (CL) systems are flash-type that generate weak luminescence and decline quickly after dozens of seconds, while the glow-type CL systems have stable emission for an extended period to achieve accurate quantitation. In this work, a long-term CL system based on hydrazine-hydrate (N2H4·H2O) modified carbon quantum dots (N-CQDs) as a luminescent probe, with K2S2O8 and H2O2 as co-reactants, was proposed. The CL emission enhanced by H2O2 increased 18-fold more than that of N-CQDs and K2S2O8 direct reaction, and decayed by 5% of the maximum intensity over 700 s. In the reaction system, K2S2O8 and H2O2 co-reactants can promote each other to continuously generate corresponding radicals (•OH, O2•-, 1O2), which in turn trigger the CL emission of N-CQDs. This phenomenon was identified as the primary cause for the production of persistent CL. In addition, a stable and selective CL sensor based on the N-CQDs-K2S2O8-H2O2 CL enhancing system was developed for ascorbic acid quantitation in the linear range from 0.1 to 10.0 mM with a detection limit of 0.036 mM. The method has been applied to the analysis of tablet samples and holds potential in pharmaceutical analysis field.
摘要：
大多数已知的化学发光（CL）系统是闪光型的，产生微弱的发光，并在几十秒后迅速下降。而辉光型CL系统具有长时间的稳定发射，以实现准确的定量。在这项工作中,以水合肼(N2H4·H2O)修饰的碳量子点(N-CQDs)为发光探针,以K2S2O8和H2O2为共反应物，被提议了。H2O2增强的CL发射比N-CQDs和K2S2O8直接反应增加了18倍，并在700s内衰减最大强度的5％。在反应系统中，K2S2O8和H2O2共反应物可以相互促进连续产生相应的自由基（•OH，O2•-，1O2),这又触发了N-CQDs的CL发射。这种现象被确定为产生持久性CL的主要原因。此外,开发了基于N-CQDs-K2S2O8-H2O2CL增强系统的稳定和选择性CL传感器，用于在0.1至10.0mM的线性范围内对抗坏血酸进行定量，检出限为0.036mM。该方法已应用于片剂样品的分析，在药物分析领域具有潜力。
