Nanobioanalysis Lab

본 연구실은 나노기술과 바이오기술의 융합기술 영역을 화학자의 관점에서 해석하고 접근하여, 바이오물질 대한 유용한 나노분석 수단을 제공하는 것에 주된 관심을 가지고 있으며, 이를 위해 나노 리소그래피, 표면개질 기술 및 나노입자의 합성법 등의 다양한 나노소재 개발을 수행하고 있다. Aspergillus niger (A. niger) is a well-known allergenic, harmful fungus in the indoor environment that can cause asthmatic symptoms and atopy. Previous immunosensing approach suffers from an insufficient detection limit, mainly because there are no techniques for target amplification. We report an electrochemical immunosensor that selectively quantifies the A. niger based on the detection of extracellular proteins by using a specific interaction with antibody. The sensor was designed to show a decrease in redox current upon binding of the antigens secreted from A. niger onto an antibody-immobilized surface between the interdigitated electrodes. The extracellular proteins were profiled by LC-MS/MS to identify the antigens existing in the A. niger solution. Since the targets of the sensor are the proteins, its sensitivity and selectivity remain almost intact even after filtration of the spores. It was also found that the use of secretion promoter in the sampling stage greatly improved the sensor’s limit of detection (LOD) for the spores. By this, the LOD was lowered by a few orders of magnitude so as to reach the value as low as ~101 spores/mL. Quantitation without relying on the calibration curve has long been an issue of overcoming analytical problems accompanied with the inherent limitations of the calibration curve fitting errors. Here, we report on a calibration curve-free method for electrochemical quantitation based on a multi-scale gap device (MGD). The MGD is an integrated device having a series of interdigitated electrodes (IDE) with micro-to-nano gap distances. The device shows a gap-dependent redox current