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 similar to 20 nm and surface plasmon resonance absorption peak at similar to 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 mu g/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.

Automated summary

In this study, specific single-chain variable fragment (scFv) antibody-conjugated Au NPs were synthesized and loaded on nitrocellulose membrane pads to design a selective lateral flow immunoassay test strip for Neisseria meningitidis. The minimum detectable bacterial concentration was found to be 0.5 μg/mL in three minutes. The molecular structure of the scFv antibody-Au NPs and the protein's Z-score confirmed their suitability for use.