Quantitative Spectrochip-Coupled Lateral Flow Immunoassay Demonstrates Clinical Potential for Overcoming Coronavirus Disease 2019 Pandemic Screening Challenges

Kai-Feng Hung; Chih-Hsing Hung; Chitsung Hong; Szu-Chia Chen; Yi-Chen Sun; Jyun-Wei Wen; Chao-Hung Kuo; Cheng-Hao Ko; Chao-Min Cheng

doi:10.3390/mi12030321

Quantitative Spectrochip-Coupled Lateral Flow Immunoassay Demonstrates Clinical Potential for Overcoming Coronavirus Disease 2019 Pandemic Screening Challenges

Micromachines (Basel). 2021 Mar 18;12(3):321. doi: 10.3390/mi12030321.

Authors

Kai-Feng Hung^{1

2}, Chih-Hsing Hung^{3

4}, Chitsung Hong⁵, Szu-Chia Chen^{6

7}, Yi-Chen Sun⁸, Jyun-Wei Wen⁵, Chao-Hung Kuo^{7

9}, Cheng-Hao Ko^{5

10}, Chao-Min Cheng¹¹

Affiliations

¹ Division of Translational Research, Department of Medical Research, Taipei Veterans General Hospital, Taipei 112, Taiwan.
² Department of Dentistry, School of Dentistry, National Yang-Ming University, Taipei 112, Taiwan.
³ Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
⁴ Department of Pediatrics, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
⁵ Spectrochip Inc., Hsinchu 300, Taiwan.
⁶ Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
⁷ Department of Internal Medicine, Kaohsiung Municipal Siaogang Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
⁸ Department of Ophthalmology, Taipei Tzu Chi Hospital, The Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan.
⁹ Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
¹⁰ Graduate Institute of Automation and Control, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
¹¹ Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan.

Abstract

As coronavirus disease 2019 (COVID-19) continues to spread around the world, the establishment of decentralized severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) diagnostics and point-of-care testing is invaluable. While polymerase chain reaction (PCR) has been the gold standard for COVID-19 screening, serological assays detecting anti-SARS-CoV-2 antibodies in response to past and/or current infection remain vital tools. In particular, lateral flow immunoassay devices are easy to produce, scale, distribute, and use; however, they are unable to provide quantitative information. To enable quantitative analysis of lateral flow immunoassay device results, microgating technology was used to develop an innovative spectrochip that can be integrated into a portable, palm-sized device that was capable of capturing high-resolution reflectance spectrum data for quantitative immunoassay diagnostics. Using predefined spiked concentrations of recombinant anti-SARS-CoV-2 immunoglobulin G (IgG), this spectrochip-coupled immunoassay provided extraordinary sensitivity, with a detection limit as low as 186 pg/mL. Furthermore, this platform enabled the detection of anti-SARS-CoV-2 IgG in all PCR-confirmed patients as early as day 3 after symptom onset, including two patients whose spectrochip tests would be regarded as negative for COVID-19 using a direct visual read-out without spectral analysis. Therefore, the quantitative lateral flow immunoassay with an exceptionally low detection limit for SARS-CoV-2 is of value. An increase in the number of patients tested with this novel device may reveal its true clinical potential.

Keywords: coronavirus disease 2019 (COVID-19); detection limit; lateral flow immunoassay; reflectance spectrum; severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2).