Projects

Label-free, ELISA-Like detection of small molecules for point-of-care testing

Description: The analysis of small-molecule metabolites and drugs in body fluids and tissue extracts plays a vital role in human health, food safety and environmental monitoring. Small molecule detection is traditionally associated with complex, time- and resource-consuming technologies, such as mass spectrometry. In contrast, antibody-based approaches, such as enzyme-linked immunosorbent assays (ELISAs), can be performed in almost any condition, with easily interpretable results available within a few hours. However, antibodies against small molecules are difficult to obtain by animal immunization because small molecules, by themselves, are non-immunogenic, and can only elicit antibodies upon conjugation to protein carriers. In addition, the detection assays require the labeling of small molecules—i.e., chemical linking of small molecule targets or their competitive inhibitors to solid support or reporter molecules—and thus, are not generally applicable because some modifications are difficult to chemically synthesize or can affect small molecule binding activity. To overcome these limitations, we applied chemically induced dimerization (CID) to small molecule detection. With collaborators, we are coupling CID proteins to point-of-care testing assays.

Funding: University of Washington Innovation Award

Related publication:

  1. COMBINES-CID: An Efficient Method for De Novo Engineering of Highly Specific Chemically Induced Protein Dimerization Systems. Shoukai Kang, Kristian Davidsen, Luis Gomez-Castillo, Huayi Jiang, Xiaonan Fu, Zengpeng Li, Yu Liang, Molly Jahn, Mahmoud Moussa, Frank DiMaio & Liangcai Gu#, Journal of the American Chemical Society, 2019, 141, 10948

  2. Synthetic Nanobody-Functionalized Nanoparticles for Accelerated Development of Rapid, Accessible Detection of Viral Antigens. Xiahui Chen*, Shoukai Kang*, Ashif Ikbal*, Zhi Zhao, Yuxin Pan, Jiawei Zuo, Liangcai Gu#, Chao Wang#, Biosensors and Bioelectronics, 2022, 202 (doi: https://doi.org/10.1016/j.bios.2022.113971).