Local Electric Potential-Driven Nanofluidic Ion Transport for Ultrasensitive Biochemical Sensing

作者：Qun Ma, Wenjing Chu, Xianliang Nong, Jing Zhao, Hong Liu, Qiujiao Du, Jielin Sun, Jianlei Shen, Si‐Min Lu, Meihua Lin, Yu Huang, Fan Xia · 发表于：ACS Nano · 年份：2024 · DOI：10.1021/acsnano.3c12547 · 被引用次数：25 · 研究领域：Nanopore and Nanochannel Transport Studies、Fuel Cells and Related Materials、Microfluidic and Capillary Electrophoresis Applications

Nanofluidic biosensors have been widely used for detection of analytes based on the change of system resistance before and after target-probe interactions. However, their sensitivity is limited when system resistance barely changes toward low-concentration targets. Here, we proposed a strategy to address this issue by means of target-induced change of local membrane potential under relatively unchanged system resistance. The local membrane potential originated from the directional diffusion of photogenerated carriers across nanofluidic biosensors and gated photoinduced ionic current signal before and after target-probe interactions. The sensitivity of such biosensors for the detection of biomolecules such as circulating tumor DNA (ctDNA) and lysozyme exceeds that of applying a traditional strategy by more than 3 orders of magnitude under unchanged system resistance. Such biosensors can specifically detect the small molecule biomarker in the blood sample between prostate cancer patients and healthy humans. The key advantages of such nanofluidic biosensors are therefore complementary to traditional nanofluidic biosensors, with potential applications in a point-of-care analytical tool.