Abstract

In this study, we report a new ratiometric electrochemical sensor to accurately and selectively detect hydrogen sulfide (H₂S) in biological samples. In this system, it contains electroactive Ag dendritic nanocomposites (NCs) as a special recognition element of H₂S and methylene blue (MB) as an inner reference molecular for a built-in correction to improve the accuracy. The Ag NCs are prepared and synthesized by a electrodeposition method, and the branches consist of rounded and smooth segments with a diameter of about 300 nm. In the presence of H₂S, combining with the good adsorption ability of GO and more active sites of dendritic Ag nanostructure, the Ag NCs of GO/MB/Ag can be oxidized to Ag₂S in the oxygen environment, resulting in the decrease of electrochemical oxidation peaks of Ag (0.42 V) and constant of current responses of MB. On the basis of the ratio of I_Ag/I_MB at two distinct potentials, the developed ratiometric electrochemical sensor displays a wide linear range from 30 to 500 μM with high accuracy, selectivity, and stability. This strategy provides a reliable and feasible method for the detections of H₂S in real samples, including biological samples related to physiological and pathological events of hydrogen sulfide production.

Graphical abstract

中文翻译：

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一种使用电活性GO / MB / Ag纳米复合材料的新型比例电化学传感器，用于生物样品中H 2 S的检测

摘要

在这项研究中，我们报告了一种新的比率式电化学传感器，可以准确，选择性地检测生物样品中的硫化氢（H ₂ S）。在该系统中，它包含电活性Ag树突状纳米复合材料（NCs）作为H ₂ S的特殊识别元素，并包含亚甲基蓝（MB）作为内部参考分子，用于内置校正以提高准确性。Ag NCs是通过电沉积方法制备和合成的，其分支由直径约300 nm的圆滑段组成。在H ₂ S存在下，结合GO的良好吸附能力和树枝状Ag纳米结构的更多活性位，GO / MB / Ag的Ag NCs可以被氧化为Ag ₂S在氧气环境中，导致Ag（0.42 V）的电化学氧化峰减少，MB的电流响应恒定。基于在两个不同电势下I _Ag / I _MB的比率，开发的比率式电化学传感器显示了30至500μM的宽线性范围，具有高精度，高选择性和稳定性。该策略为实际样品中的H ₂ S检测提供了一种可靠可行的方法，其中包括与硫化氢生产的生理和病理事件有关的生物样品。