新型ECL三元体系构建传感平台用于高灵敏检测多巴胺

The Sensor Platform of the New ECL Ternary System for Highly Sensitive Detection of Dopamine

碳点(CDs)作为一类具有毒性低、生物相容性好等优点的新型电致化学发光(ECL)材料在生物检测方面展现出广阔的应用前景,但是目前存在发光信号不稳定、强度弱等问题。为了解决这些问题,该工作通过提供合适的固载基质和共反应促进剂,有效改进了CDs的ECL性能。首先,用二氧化硅(SiO_(2))包覆制备的CDs,其中SiO_(2)作为固载基质可以有效减少CDs的自聚集问题。其次,针对CDs的发光强度弱的问题,提出一种新型的三元ECL体系,在复合材料CDs@SiO_(2)表面原位还原银纳米粒子(Ag NP),促进共反应试剂S_(2)O_(8)^(2-)的自由基中间体(SO_(4)^(·-))生成效率,从而有效提高CDs的ECL强度。基于AgNP-CDs@SiO_(2)构建的ECL传感平台呈现出对多巴胺(DA)的高灵敏响应性能,其检测范围为10^(-2)mol/L至10^(-7)mol/L,检测限低至8.86 nmol/L。该工作为设计新型ECL体系提供了思路,为疾病标志物的检测提供参考。

Carbon dots(CDs),as a new kind of electrochemiluminescence(ECL)materials with low cytotoxicity and excellent biocompatibility,have shown a broad application prospect in biological detection.However,there are some issues such as unstable and weak luminous signals.In order to solve these problems,this work effectively improves the ECL performance of CDs by providing suitable immobilized substrates and co-reaction accelerators.Firstly,CDs were wrapped by silica(SiO_(2)),and SiO_(2)as the immobilized substrate can effectively reduce the selfaggregation of CDs.Secondly,a new ternary ECL system is proposed to solve the weak luminous intensity of CDs.Silver nanoparticle(Ag NP)was in-situ reduced on the surface of composite material(CDs@SiO_(2))to promote the formation efficiency of intermediate free radical(SO_(4)^(·-))from co-reactive reagent S_(2)O_(8)^(2-),thus effectively enhancing the ECL intensity of CDs.The ECL sensor platform constructed based on AgNP-CDs@SiO_(2)shows highly responsive performance to dopamine(DA),with detection range of 10^(-2)mol/L to 10^(-7)mol/L and detection limit as low as 8.86 nmol/L.This work provides a idea for the design of novel ECL system and a reference for the detection of disease markers.