School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia.
School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia; Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia.
Anal Chim Acta. 2021 Nov 15;1185:339082. doi: 10.1016/j.aca.2021.339082. Epub 2021 Sep 20.
Cardiac troponin I (cTnI) is a sensitive biomarker for cardiovascular disease (CVD). Rapid determination of cTnI concentration in blood can greatly reduce the potential of significant heart damage and heart failure. Herein, we demonstrate a new electrochemical immunosensor for selective affinity binding and rapid detection of cTnI in blood plasma by an electrochemical method. A conductive film of "poly 2,5-bis(2-thienyl)3,4-diamine-terthiophene (PDATT)" was deposited onto an Indium Tin Oxide (ITO) electrode using chronoamperometry. Anti-cardiac troponin I antibody was then attached to the two amine (NH) groups substituted on the central thiophene of terthiophene repeating unit of the polymer chain via amide bond formation. The gaps on the surface of the antibody coated immunosensor were backfilled with bovine serum albumin (BSA) to prevent nonspecific binding of interfering molecules. Differential pulse voltammetry (DPV) was used to determine cTnI upon the formation of cTnI immunocomplex on the sensing surface, appearing a peak at 0.27 V. The response range was 0.01-100 ng mL with limit of quantification down to 0.01 ng mL. The developed immunosensor was used to determine cTnI in spiked blood plasma without interference from cardiac troponin T (cTnT). Therefore, this new sensor can be utilised for the detection of cTnI biomarker in pathological laboratories and points of care in less than 15 min.
心肌肌钙蛋白 I（cTnI）是心血管疾病（CVD）的敏感生物标志物。快速测定血液中的 cTnI 浓度可以大大降低发生严重心脏损伤和心力衰竭的风险。在此，我们通过电化学方法展示了一种新的电化学免疫传感器，用于选择性亲和结合和快速检测血浆中的 cTnI。通过计时安培法在氧化铟锡（ITO）电极上沉积了一层“聚 2,5-双（2-噻吩基）3,4-二胺-三噻吩（PDATT）”的导电膜。然后，通过酰胺键形成将抗心肌肌钙蛋白 I 抗体连接到聚合物链的三噻吩重复单元的中心噻吩上的两个氨基（NH）基团上。抗体涂覆免疫传感器表面的间隙通过牛血清白蛋白（BSA）回填以防止干扰分子的非特异性结合。差分脉冲伏安法（DPV）用于在传感表面上形成 cTnI 免疫复合物后测定 cTnI，在 0.27 V 处出现峰。响应范围为 0.01-100ng mL，定量下限低至 0.01ng mL。该开发的免疫传感器可用于在没有心肌肌钙蛋白 T（cTnT）干扰的情况下检测加标血浆中的 cTnI，因此，这种新的传感器可用于在病理实验室和护理点在 15 分钟内检测 cTnI 生物标志物。
