Department of Chemistry, Federal University of São Carlos, São Carlos 13565-905, SP, Brazil.
Department of Chemistry, Federal University of Maranhão, São Luís 65080-805, MA, Brazil.
Biosensors (Basel). 2023 Mar 13;13(3):379. doi: 10.3390/bios13030379.
A sensitive and selective label-free photoelectrochemical (PEC) immunosensor was designed for the detection of cardiac troponin I (cTnI). The platform was based on a fluorine-doped tin oxide (FTO)-coated glass photoelectrode modified with bismuth vanadate (BiVO) and sensitized by an electrodeposited bismuth sulfide (BiS) film. The PEC response of the BiS/BiVO/FTO platform for the ascorbic acid (AA) donor molecule was approximately 1.6-fold higher than the response observed in the absence of BiS. The cTnI antibodies (anti-cTnI) were immobilized on the BiS/BiVO/FTO platform surface to produce the anti-cTnI/BiS/BiVO/FTO immunosensor, which was incubated in cTnI solution to inhibit the AA photocurrent. The photocurrent obtained by the proposed immunosensor presented a linear relationship with the logarithm of the cTnI concentration, ranging from 1 pg mL to 1000 ng mL. The immunosensor was successfully employed in artificial blood plasma samples for the detection of cTnI, with recovery values ranging from 98.0% to 98.5%.
一种灵敏且选择性的无标记光电化学（PEC）免疫传感器被设计用于检测心肌肌钙蛋白 I（cTnI）。该平台基于氟掺杂氧化锡（FTO）涂层玻璃光电电极，修饰有五氧化二铋（BiVO），并敏化有电沉积硫化铋（BiS）薄膜。BiS/BiVO/FTO 平台对抗坏血酸（AA）供体分子的 PEC 响应大约比没有 BiS 时观察到的响应高 1.6 倍。cTnI 抗体（抗-cTnI）被固定在 BiS/BiVO/FTO 平台表面上，产生抗-cTnI/BiS/BiVO/FTO 免疫传感器，该传感器在 cTnI 溶液中孵育以抑制 AA 光电流。所提出的免疫传感器获得的光电流与 cTnI 浓度的对数呈线性关系，范围从 1 pg mL 到 1000 ng mL。该免疫传感器成功地用于人工血浆样品中 cTnI 的检测，回收率范围为 98.0%至 98.5%。
