Our multidisciplinary research focuses on nano-micro-macro scale devices for biomedical applications. We develop and deploy innovative functional materials, devices, and systems to enable next-generation medical diagnosis and life science research.
The projects performed to achieving our over-arching goals are listed below.
I. Point-of-care nucleic acid testing (NAT)
Nucleic acid testing (NAT) is currently the most sensitive method available for identifying infectious pathogens. Nevertheless, NAT-based diagnosis developed to date mostly require sophisticated infrastructures, reagents, and skilled technicians. While readily available in reference laboratories, NATs such as PCR remains inaccessible in resource-limited settings. Although extensive efforts have been undertaken towards point-of-care (POC) molecular diagnosis, a fully validated “sample-in-answer-out” NAT system has not developed due to significant challenges of portability, sample preparation, and throughput. In response to this urgent need, we aim to develop low-cost field-deployable field-deployable NAT devices and systems, especially for infectious disease in resource-limiting areas. These NAT devices could be loaded with easily-obtainable raw biospecimen such as finger prick blood, making diagnostic testing faster and easier for identifying pathogens like Malaria, Zika, and HIV.
- G. Choi, T. Prince, J. Miao, L. Cui, and W. Guan. Sample-to-answer palm-sized nucleic acid testing device towards low-cost malaria mass screening. Biosensors and Bioelectronics, 115, 83 (2018)
- G. Choi, D. Song, S. Shrestha, J. Miao, L. Cui, and W. Guan. A field-deployable mobile molecular diagnostic system for malaria at the point of need. Lab on a Chip, 16, 4341 (2016).
II. Nanofluidics: device physics, fabrication, and biosensing application
Nanopores and nanochannels offer unique platforms to explore new physical and chemical phenomena appearing for molecule confined in or transported through these structures. New transport behavior and biosensing functionalities can be developed by taking advantage of these unique phenomena occurring at these scales. We study solid-state nanopores and solid-state nanochannels with the aim to understand the device physics, to explore viable fabrication and integration methods, and to develop single molecule sensing applications.
- K. Roshan, Z. Tang, and W. Guan. High fidelity moving Z-Score based controlled breakdown fabrication of solid-state nanopore. Nanotechnology, 30, 095502 (2019).
- X. Li, W. Guan, B. Weiner, and M. A. Reed. Direct Observation of Charge Inversion in Divalent Nanofluidic Devices. Nano Letters, 15, 5046 (2015).
- W. Guan, and M. A. Reed. Electric Field Modulation of the Membrane Potential in Solid-State Ion Channels. Nano Letters, 12, 6441 (2012).
- W. Guan, R. Fan, and M. A. Reed. Field-effect reconfigurable ionic diode. Nature Communications, 2, 506 (2011).
III. Cell Mechanotyping
The mechanical behavior of individual cells plays an important role in regulating various biological activities at the molecular and cellular level. It can serve as a promising label-free marker of cells’ physiological states. In the past decades, several technologies have been developed for understanding the association between cell mechanical changes and human diseases. However, numerous technical challenges still remain for realizing high-throughput, robust and easy-to-perform measurements on single-cell mechanical properties.
- X. Yang, Z.Chen, J. Miao, L. Cui, and W. Guan. High-throughput and label-free parasitemia quantification and stage differentiation for malaria-infected red blood cells. Biosensors and Bioelectronics, 98, 408 (2017).