Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

Vertical Nanogap Arrays Assembled from Nanoentities for Highly Sensitive Biochemical Detection

Nguyen Hoang Minh1,2, Jae Sung Yoon1,2, Do Hyun Kang1, Yeong-Eun Yoo1,2 and Kwanoh Kim1,a

1Department of Nano Manufacturing Technology, Korea Institute of Machinery and Materials (KIMM), 156 Gajeongbuk-ro, Daejeon, 34103, South Korea

2Department of Nano-Mechatronics, University of Science and Technology (UST), 217 Gajeong-ro, Daejeon, 34113, South Korea


Nanogap-based biosensors have emerged as promising platforms for detecting and measuring biochemical substances at low concentrations. Although the nanogap biosensors provide high sensitivity, low limit of detection (LOD), and enhanced signal strength, it requires arduous fabrication processes and costly equipment to obtain micro/nanoelectrodes with extremely narrow gaps in a controlled manner. In this work, we report the novel design and fabrication processes to construct vertical nanogap structures that can electrically detect and quantify low-concentration biochemical substances. By magnetically assembling bioreceptor-functionalized nanowires onto a nanodisk patterned between a pair of microelectrodes, ~40-nm gaps are facilely formed between the nanowires and the microelectrodes. Analyte molecules attached to conductive gold nanoparticles are captured and bound to the surface of the nanowires and bridge over the nanogaps, which consequently causes an abrupt change in the electrical conductivity measured between the microelectrodes. Using biotin and streptavidin as model bioreceptors and analytes, we demonstrate that our nanogap biosensors can effectively measure the protein analytes in the range of 50 – 100 pM with great linearity. The outcome of this research could inspire the design and fabrication of nanogap electrical devices and nanobiosensors, and it would have a broad impact on the development of microfluidics, biochips, and lab-on-a-chip architectures.

Keywords: Nanoassembly, Magnetic interaction, Nanomanipulation, Resistive biosensor, Protein electronics.

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