Miland E, Miranda Ordieres A J, Tuñón Blanco P, Smyth M R, Fágáin C O
Departamento de Química-Física y Analitica, Universidad de Oviedo, Oviedo, Asturias, Spain.
Talanta. 1996 May;43(5):785-96. doi: 10.1016/0039-9140(95)01825-5.
A reagentless uric acid selective biosensor constructed by immobilising uricase and horseradish peroxidase (HRP) in carbon paste without the addition of an electron transfer mediator is described. The response of the electrode is based on the enzymatic reduction of hydrogen peroxide in the presence of uric acid. Uricase and HRP were dispersed in the carbon paste and the optimum paste mixture was determined. Poly(o-aminophenol) was electropolymerised at the working surface area of the electrode acting as a conducting polymer layer. Cyclic voltammetry was used to characterise the permselective characteristics of the polymer layer. At an applied potential of 50 mV vs. Ag/AgCl, a linear response was obtained up to 1 x 10(-4) M, with a limit of detection of 3 x 10(-6) M. The sensor had a response time of 37 s. a calibration precision of 2.2% (n = 4) and an estimated sample frequency of 20 h(-1). Responses to the analyte of interest were pH dependent. The sensor was incorporated into a flow injection system for the qualification of uric acid in human serum. Results compared favourably with a standard spectrophotometric method.
本文描述了一种无试剂尿酸选择性生物传感器，该传感器通过将尿酸酶和辣根过氧化物酶（HRP）固定在碳糊中构建而成，无需添加电子传递介质。电极的响应基于在尿酸存在下过氧化氢的酶促还原反应。将尿酸酶和HRP分散在碳糊中并确定了最佳糊剂混合物。在电极的工作表面积上对聚（邻氨基酚）进行电聚合，形成导电聚合物层。采用循环伏安法表征聚合物层的选择性透过特性。在相对于Ag/AgCl为50 mV的外加电位下，浓度高达1×10⁻⁴ M时获得线性响应，检测限为3×10⁻⁶ M。该传感器的响应时间为37 s，校准精度为2.2%（n = 4），估计采样频率为20 h⁻¹。对目标分析物的响应取决于pH值。该传感器被集成到流动注射系统中用于检测人血清中的尿酸。结果与标准分光光度法相比具有优势。
