Graduate Student
Seoul National University, BS
Chemical Engineering
seunghk@mit.edu
Research
Polymerization-based signal amplification (PBA) is a method of amplifying the signal of molecular recognition events in a biosensor using inherent amplification in photo-initiated radical polymerization. PBA is a promising tool for the diagnosis of diseases in resource-limited settings because it is not only easy to use and rapid, but it can also quantitatively measure the concentration of target molecules in patients’ samples without expensive analytical equipment. Recently, PBA has proven its superiority to other competing methods based on enzymes and gold nanoparticles in terms of user-friendliness because of its high contrast and time-independent visualization. However, PBA is not sensitive enough to detect sub-nanomolar concentration of analytes, which has made it unsuitable for early diagnosis of many infectious diseases. Thus, the limit of detection (LOD) of PBA must be improved for its practical use in the field.
My research focuses on improving the LOD of PBA. The first aim is to localize photoinitiators on a binding zone only in the presence of target species because the more photoinitiators are on the binding zone, the stronger the PBA signal will be. The second aim is to understand the reaction mechanism of PBA based on spectroscopic experiments and develop a reaction-diffusion model to optimize PBA parameters in any geometries to improve the LOD of PBA. With these approaches, I hope to improve the LOD of PBA from nM to pM and reduce false negative and false positive errors.
Publications
Carmen Tobos*, Seunghyeon Kim*, David Rissin, Joseph Johnson, Scott Douglas, Susan Yan, Shuai Nie, Bradley Rice, Ki-Joo Sung, Hadley Sikes, David Duffy. “Sensitivity and Binding Kinetics of an Ultra-Sensitive Chemiluminescent Enzyme-Linked Immunosorbent Assay at Arrays of Antibodies,” Journal of Immunological Methods, 2019, in press. *these authors contributed equally
Seunghyeon Kim and Hadley D. Sikes. “Liposome-enhanced polymerization-based signal amplification for highly sensitive naked-eye biodetection in paper-based sensors,” ACSApplied Materials and Interfaces, 2019, 11 (31), 28469-28477. DOI: 10.1021/acsami.9b08125.
Alan Aguirre-Soto, Kaja Kaastrup, Seunghyeon Kim, Kasite Ugo-Beke, Hadley D. Sikes. “Excitation of metastable intermediates in organic photoredox catalysis: Z-scheme approach decreases catalyst inactivation,” ACS Catalysis,” 2018. DOI:10.1021/acscatal.8b00857.