Immunodiagnostic of Vibrio cholerae O1 using localized surface plasmon resonance (LSPR) biosensor.

V. cholerae O1 is a gram-negative bacilli that causes an acute gastrointestinal disease called cholera. V. cholerae can enter into the biofilm phase in a period of life; hence, it is challenging to recognize these bacteria. Accordingly, using localized surface plasmon resonance (LSPR) features of the nanoparticles, an accurate detection method based on the antigen-antibody reaction was used. Ordinarily, immobilization of plasmonic nanoparticles by monoclonal antibodies was performed and UV-visible spectroscopy, dynamic light scattering (DLS), and zeta potential (Zp) measurements verified the conjugation process. In the vicinity of several concentrations of V. cholerae O1, the consistency of the engineered nanobioprobe was then investigated using LSPR monitoring and colorimetric assay. Finally, the ELISA and PCR techniques contrasted the sensitivity of nanobiosensors. The results showed that by applying monoclonal antibodies as a sensor feature, the nanobioprobe showed high sensitivity to target bacterial analysis. Thus, the limit of detection in this immunoassay-based biosensor was calculated to be a sharp reduction in the absorption of 10 CFU/mL of V. cholerae O1 with approximately 5 nm of redshift, while the shift of light refraction in the LSPR band was extended to approximately 18 nm by raising the antigen concentration to 10 CFU/mL. This LSPR biosensor can therefore be used for V. cholerae O1 (Inaba strain) detection as a simple, sensitive, and reliable diagnostic tool. In conclusion, the built biosensor will facilitate and speed up V. cholerae O1 (Inaba strain) classification by controlling the specific antigen to prevent the unintended spread of cholera disease.