Enhancing antibody detection sensitivity in lateral flow immunoassays using endospores of Bacillus subtilis as signal amplifiers

Wen-Zhi Lin; Chin-Mao Hung; I-Hsien Lin; Yi-Jia Sun; Zheng-Xiu Liao; Chia-Chun Wu; Shao-Yi Hou

doi:10.1016/j.talanta.2024.126215

Enhancing antibody detection sensitivity in lateral flow immunoassays using endospores of Bacillus subtilis as signal amplifiers

Talanta. 2024 May 6:276:126215. doi: 10.1016/j.talanta.2024.126215. Online ahead of print.

Authors

Wen-Zhi Lin¹, Chin-Mao Hung², I-Hsien Lin³, Yi-Jia Sun⁴, Zheng-Xiu Liao⁵, Chia-Chun Wu⁶, Shao-Yi Hou⁷

Affiliations

¹ Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, Taipei, 11490, Taiwan; Institute of Preventive Medicine, National Defense Medical Center, New Taipei City, 23742, Taiwan; Department of Biology and Anatomy, National Defense Medical Center, Taipei, 11490, Taiwan. Electronic address: takashi@mail.ndmctsgh.edu.tw.
² Institute of Preventive Medicine, National Defense Medical Center, New Taipei City, 23742, Taiwan; Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, 11490, Taiwan. Electronic address: 802010346@mail.ndmctsgh.edu.tw.
³ Graduate Institute of Chemical Engineering, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 10608, Taiwan. Electronic address: anniebaou1234@gmail.com.
⁴ Graduate Institute of Biochemical and Biomedical Engineering, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 10608, Taiwan. Electronic address: t110688026@ntut.org.tw.
⁵ Graduate Institute of Chemical Engineering, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 10608, Taiwan. Electronic address: t110688018@ntut.edu.tw.
⁶ Institute of Preventive Medicine, National Defense Medical Center, New Taipei City, 23742, Taiwan; Department of Orthopaedic Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, 11490, Taiwan. Electronic address: doc20281@gmail.com.
⁷ Graduate Institute of Biochemical and Biomedical Engineering, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, 10608, Taiwan. Electronic address: f10955@ntut.edu.tw.

PMID: 38723474
DOI: 10.1016/j.talanta.2024.126215

Abstract

Antibody detection is the critical first step for tracking the spread of many diseases including COVID-19. Lateral flow immunoassay (LFIA) is the most commonly used method for rapid antibody detection because it is easy-to-use and inexpensive. However, LFIA has limited sensitivity when gold nanoparticles (AuNPs) are used as the signals. In this study, the endospores of Bacillus subtilis were used in combination with AuNP in a LFIA to detect antibodies. The endospores serve as a signal amplifier. The detection limit was about 10^-8 M for anti-beta galactosidase antibody detection whereas the detection limit of conventional LFIA is about 10^-6 M. Furthermore, the proposed methods have no additional user steps compared with the traditional LFIA. This method, therefore, improved the sensitivity 100-fold without compromising any advantages of LFIA. We believe that the proposed method will be useful for detection of antibodies against HIV, Zika virus, SARS-CoV-2, and so on.

Keywords: Antibody detection; Bacillus subtilis; Endospores; Gold nanoparticles; Lateral flow immunoassays.