A novel modified carbon paste electrode (CPE) based on an MnO₂‐TiO₂ nanocomposite and 2‐(3,4 dihydroxyphenethyl) isoindoline‐1,3‐dione (DPID) as the modifier for the simultaneous analysis of cysteine (Cys), tryptophan (Trp) and uric acid (UA), as three key biochemicals present in human body. The MnO₂/TiO₂ nanocomposite was synthesized through a chemical co‐precipitation approach and the resulting electrode (MnO₂‐TiO₂/DPID/CPE) was used for studying the electrochemical oxidation of cysteine (Cys), tryptophan (Trp) and uric acid. As opposed to conventional CPEs, the oxidation peak potential of cysteine on MnO₂‐TiO₂/DPID/CPE had a 600.0 mV decrease in overpotential and could be observed at 30.0 mV, and the signals were linear from 0.025 to 200.0 μM, and a lower detection limit of 0.013 μM was reached. The MnO₂‐TiO₂/DPID/CPE was satisfactorily used for the concurrent analysis of Cys, Trp and UA in pharmaceutical and biological samples.

中文翻译：

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MnO2-TiO2纳米复合材料和2-（3,4-二羟基苯乙基）异吲哚啉-1,3-二酮作为同时测定半胱氨酸，色氨酸和尿酸的电化学平台

一种基于MnO ₂ -TiO ₂纳米复合材料和2-（3,4-二羟基苯乙基）异吲哚啉-1,3-二酮（DPID）作为修饰剂的新型修饰碳糊电极（CPE），用于同时分析半胱氨酸（Cys），色氨酸（Trp）和尿酸（UA），是人体中存在的三种主要生化物质。通过化学共沉淀法合成了MnO ₂ / TiO ₂纳米复合材料，并将所得电极（MnO ₂ -TiO ₂ / DPID / CPE）用于研究半胱氨酸（Cys），色氨酸（Trp）和尿酸的电化学氧化酸。与常规CPE相比，半胱氨酸在MnO ₂ -TiO ₂上的氧化峰电位/ DPID / CPE的过电势降低了600.0 mV，可以在30.0 mV处观察到，信号在0.025至200.0μM之间呈线性，检测下限达到0.013μM。MnO ₂ -TiO ₂ / DPID / CPE可令人满意地用于药物和生物样品中Cys，Trp和UA的同时分析。