Laboratório de Pesquisa em Diagnóstico/LAPED, Pronto Socorro Cardiológico de Pernambuco/PROCAPE, Universidade de Pernambuco, Rua dos Palmares, s/n, 50100-130 Recife-PE, Brazil.
Biosens Bioelectron. 2010 Nov 15;26(3):1062-7. doi: 10.1016/j.bios.2010.08.051. Epub 2010 Aug 21.
Screen-printed electrodes (SPE) have been widely used in the design of disposable sensors bringing advances in the use of electrochemical immunosensors for in field-clinical analysis. In this work, streptavidin polystyrene microspheres were incorporated to the electrode surface of SPEs in order to increase the analytical response of the cardiac troponin T (cTnT), a specific biomarker for the acute myocardial infarction diagnosis. The precise calculation of the stoichiometric streptavidin-biotin ratio [1:4] allowed the increase of sensitivity and stability of the immunosensor response to the cTnT analyte. The surface of the immunosensor was characterized by scanning electron microscopy and cyclic voltammetry. It was observed that the use of streptavidin microspheres significantly increased the analytical sensitivity of the electrode in 8.5 times, showing a curve with a linear response range between 0.1 and 10 ngmL(-1) of cTnT and a detection limit of 0.2 ngmL(-1). The proposed SPE showed ease preparation and high sensitivity allowing the detection of cTnT in the range of clinical levels. The new device coupled with a portable electrochemical analyzer shows great promise for point-of-care quantitative testing of necrosis cardiac proteins.
丝网印刷电极 (SPE) 在一次性传感器的设计中得到了广泛应用，为电化学免疫传感器在现场临床分析中的应用带来了进步。在这项工作中，将链霉亲和素聚苯乙烯微球掺入 SPE 的电极表面，以提高心肌肌钙蛋白 T (cTnT) 的分析响应，cTnT 是急性心肌梗死诊断的特定生物标志物。精确计算的计量比 [1:4] 链霉亲和素-生物素允许增加免疫传感器对 cTnT 分析物的响应的灵敏度和稳定性。通过扫描电子显微镜和循环伏安法对免疫传感器的表面进行了表征。观察到使用链霉亲和素微球显着提高了电极的分析灵敏度 8.5 倍，显示出 cTnT 在 0.1 至 10ngmL(-1)之间具有线性响应范围的曲线，检测限为 0.2ngmL(-1)。所提出的 SPE 具有易于制备和高灵敏度的特点，允许在临床水平范围内检测 cTnT。该新设备与便携式电化学分析仪结合使用，有望用于即时定量检测坏死心脏蛋白。
