Centre for Personalized Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), Corner College and Cooper Roads (Bldg 75), The University of Queensland, Brisbane, QLD 4072, Australia.
Nanoscale. 2018 Jun 14;10(23):10884-10890. doi: 10.1039/C7NR09496E.
Interfacial biosensing performs the detection of biomolecules at the bare-metal interface for disease diagnosis by comparing how biological species derived from patients and healthy individuals interact with bare metal surfaces. This technique retrieves clinicopathological information without complex surface functionalisation which is a major limitation of conventional techniques. However, it is still challenging to detect subtle molecular changes by interfacial biosensing, and the detection often requires prolonged sensing times due to the slow diffusion process of the biomolecules towards the sensor surface. Herein, we report on a novel strategy for interfacial biosensing which involves in situ electrochemical detection under the action of an electric field-induced nanoscopic flow at nanometre distance to the sensing surface. This nanomixing significantly increases target adsorption, reduces sensing time, and enables the detection of small molecular changes with enhanced sensitivity. Using a multiplex electrochemical microdevice that enables nanomixing and in situ label-free electrochemical detection, we demonstrate the detection of multiple cancer biomarkers on the same device. We present data for the detection of aberrant phosphorylation in the EGFR protein and hypermethylation in the EN1 gene region. Our method significantly shortens the assay period (from 40 min and 20 min to 3 minutes for protein and DNA, respectively), increases the sensitivity by up to two orders of magnitude, and improves detection specificity.
界面生物传感在裸金属界面进行生物分子的检测，通过比较患者和健康个体来源的生物物种与裸金属表面的相互作用来进行疾病诊断。该技术无需复杂的表面功能化即可获取临床病理信息，这是传统技术的主要局限性。然而，通过界面生物传感检测细微的分子变化仍然具有挑战性，并且由于生物分子向传感器表面的扩散过程缓慢，检测通常需要较长的感应时间。在此，我们报告了一种新的界面生物传感策略，该策略涉及在纳米距离处的电场诱导的纳米级流动作用下进行原位电化学检测。这种纳米混合显著增加了目标吸附，缩短了检测时间，并提高了检测灵敏度，可检测到微小的分子变化。我们使用一种可实现纳米混合和原位无标记电化学检测的多路电化学微器件，在同一器件上演示了对多种癌症生物标志物的检测。我们提供了 EGFR 蛋白中异常磷酸化和 EN1 基因区域中超甲基化的检测数据。我们的方法大大缩短了检测周期（从 40 分钟和 20 分钟分别缩短至 3 分钟，适用于蛋白质和 DNA），提高了灵敏度达两个数量级，并改善了检测特异性。
