Microfluidic biosensor devices for disease monitoring and cancer study

Zhou, Zhiru

Etd

Microfluidic biosensor devices for disease monitoring and cancer study

Public

With the recent advances in nanomaterials, biosensor design, and microfluidic technology, the point-of-care devices have shown a potential to revolutionize the future health care diagnostics and therapy practices. The intelligent use of nanomaterials is predicted to solve the challenge of efficient signal capture of the recognition event and signal amplification of the biosensor. Cu-CuO nanoparticles decorated TiO2 nanotubes were synthesized and fabricated as the electrode for non-enzymatic glucose sensor. The glucose biosensor showed great sensor performance such as high sensitivity, great specificity and wide linear detection range toward glucose. While nanomaterials modified electrode showed promising analytical performance, reliable and low-cost mass production of nanostructured electrode will further facilitate the real application for biosensors. A novel and simple method was proposed to prepare nanopattern in polymer-based electrode for biosensors. The repeatability of our method was better than traditional ones because of using a predefined mold. A polyurethane (PU) nanospiked gold electrode-based label-free electrochemical immunosensor for Clostridium difficile (C. difficile) toxin B detection was developed. The PU nanospiked gold electrode-based immunosensor showed detection limit as low as 0.5 pg/mL, good specificity and repeatability. Benefiting from its low cost and simple processing, the fabricated immunosensor can be used as a disposable electrochemical sensor for toxin B rapid detection. Microfluidic device merged as a powerful platform for the manipulation of different chemical and physical factors, mimicking physiological microenvironment, study of cell migration and metastasis, on-chip diagnostics and monitoring. I designed and fabricated a PDMS microfluidic device for the study of vimentin effect in cell migration and cancer metastasis. Using this microchannel assay, it was demonstrated that the knockdown of vimentin decreases 3T3 fibroblast cell directional migration speed in confined microchannels, meanwhile leading-edge morphologies of 3T3 fibroblast and 3T3 vimentin knockdown cells were observed to be different during migration. The integration of biosensors in microfluidic devices has great potential in stand-alone or hand-held systems for point-of-care diagnostics. Glycol-modified polyethylene terephthalate (PETG)-based microfluidic devices with embedded channels and gold film electrode (GFE) are developed by a one-step, low-cost, straightforward, and mass-producible method, and are sealed by a reversible hydrophilic tape-based mechanism. The PETG/GFE device was fabricated for simultaneous detection of cytokines on chip. Mxene nanomaterial was proposed as the probe material due to its great electron transfer ability, excellent catalytic ability and good biocompatibility. This work provides insights into nanomaterials synthesis, nanofabrication and microfabrication for microfluidic biosensor device, enhances our understanding point-of-care diagnostics platforms for disease diagnostics, cancer metastasis study and treatment, and offers a variety of diagnostics platforms for future clinical use.

Creator