Detection of Cardiac Troponin I in Serum by CMK-3/AuNPs-based Electrochemical Sensor
Dan Chen, Yong Gong, Yinsheng Jin
Abstract
In this work, a novel signal amplification strategy was proposed based on nitrogen-doped ordered mesoporous carbon (CMK-3) and AuNPs nanocomposites (CMK-3/AuNPs). An immunosensor was fabricated to detect the concentration of cTnI in blood. CMK-3/AuNPs nanocomposites were used to modify the surface of gold electrode. The immunoreaction between the anti-cTnI and the target cTnI on the sensing interface can significantly reduce the electrocatalytic performance of H 2 O 2 , thus realizing the labeled free sensing analysis of cTnI. In the range of 10 fg/mL ~ 0.1 μg/mL, the catalytic current difference (ΔI) has a good linear relationship with the logarithm of cTnI concentration. The detection limit can be calculated to be 2.4 fg/mL(S/N=3). Based on the advantages of nanocomposites, the immunosensor has the advantages of low cost, fast response, high sensitivity, wide detection range and low detection limit. In addition, the immunosensor has good specificity and stability, which can be used to distinguish cTnI from other interfering substances.