Neisseria meningitidis detection by coupling bacterial factor H onto Au/scFv antibody nanohybrids

Neisseria meningitides is one of the causative agents of the deadly bacterial meningitis disease, and its rapid diagnosis is highly required. In this study, at first, a specific single-chain variable fragment (scFv) antibody-conjugated Au NPs with average size of ~ 20 nm and surface plasmon resonance absorption peak at ~ 530 nm in wavelength were synthesized. Then, the NPs were loaded on nitrocellulose membrane pads for designing a selective lateral flow immunoassay test strip which is sensitive to the factor H protein of Neisseria meningitidis . The results showed a minimum detectable bacterial concentration of 0.5 μg/mL in only three minutes. The molecular structure of the scFv antibody-Au NPs (with the binding energy of − 4.7 kcal) has been also investigated by docking method. Furthermore, the complex Z -score (− 7.47) calculated by using ProSA software confirmed that our protein is in the range of all known Z-scores of the protein structures. Graphical abstract