This is the research topic for my bachelor’s thesis. After completing the Surface Plasmon Resonance Platform project, I acquired microfabrication techniques for fabricating microfluidic gold surface chips. The gold surface can be patterned to form a two-electrode setup, where electrochemical detection can be applied for biosensing. For this project, I fabricated a microfluidic microelectrode chip that can detect the concentration of the tumor marker MUC1 using a DNA aptamer. A method called electrochemical impedance spectroscopy (EIS) is used for detecting the change of impedance caused by different concentrations of MUC1. I won the Outstanding Poster Award for poster presentation of this work at the 64th TwIChE (Taiwan Institute of Chemical Engineers) Annual Meeting.
Introduction
Mucin 1(MUC1) is a glycoprotein which plays an important role within the human body such as cell signaling and defense of pathogens. Overexpression of MUC1 on cancer cell surfaces promotes cell survival and tumor angiogenesis. Therefore, the detection of MUC1 has become a new trend in early detection of cancer and therapy. Aptamers are synthesized DNA or RNA which serves as suitable sensing elements for targets such as MUC1 or other proteins and can achieve excellent affinity and selectivity. Electrochemical impedance spectroscopy (EIS) is a powerful electrochemical detection technique regarding its ability for monitoring different stages during the fabrication process of aptasensors. Moreover, the label-free, simple and highly sensitive features further strengthen its potential of integrating with other applications. Microfluidics are recently recognized as a technique advantageous for performing bioanalysis. Not only can they lower the amount of usage during reactions, but also have the potential to meet real-time, portable, large-scale and high-throughput requirements. In this study, a novel aptasensor for detecting MUC1 using microfluidic integrated gold electrode is fabricated and demonstrated. Parameter fitting of the equivalent circuit is performed after each step during the fabrication and protein detection. An LOD of 0.42nM is achieved and the fitting result suggests several varying element parameters influenced by the concentration of MUC1. The simple, label-free and low reagent usage detection of MUC1 using this microfluidic impedimetric aptasensor is achieved.
Related Publications
- C.-Y. Lai, L.-C. Chen, The study of an impedimetric microfluidic chip design for mucin1 aptasensing, 64th TwIChE Annual Meeting, (2017). Outstanding Poster Award
[poster pdf] - C.-Y. Lai, L.-C. Chen, Detection of mucin1 with a microfluidic impedimetric aptasensor, International Symposium on Smart-Sensing Medical Devices and 22nd Symposium of Association for Chemical Sensors in Taiwan, (2017).
[abstract] [presentation pdf] [presentation clip] - Bachelor’s thesis: The Study of an Impedimetric Microfluidic Chip Applied for MUC1 Aptasensing