A wrinkled structure of gold film greatly improves the signaling of electrochemical aptamer-based biosensors
Shaoguang Li, Lancy Lin, Xueman Chang, Zhixiao Si, Kevin W. Plaxco, Michelle Khine, Hui Li, Fan Xia
Abstract
square-wave voltammetry. This low signaling limits the sensor's precision for its capability to detect small changes in target concentrations. To circumvent this, we proposed here the use of a readily shrink-induced, wrinkled Au-coating polyolefin film to immobilize a greater number of DNA probes and thus improve the signaling. Specifically, wrinkled gold film exhibits a 5.5-fold increase of surface area in comparison to the unwrinkled ones. Using these substrates we fabricated a set of E-AB sensors of three biological molecules, including kanamycin, doxorubicin and ATP. We achieved up to 10-fold increase in its current and also good accuracies within ±20% error in the target concentration range across 2 orders of magnitude.