Use of an electro-optical sensor and phage antibodies for immunodetection of Herbaspirillum

• Published in: Talanta (Oxford) 2019-09, Vol.202, p.362-368
• Main Authors: Guliy, O.I., Velichko, N.S., Fedonenko, Yu. P., Bunin, V.D.
• Format: Article
• Language: English
• Subjects: Antibodies, Bacterial - immunology; Biosensing Techniques; Detection; Electro-optical sensor; Electrochemical Techniques; Enzyme-Linked Immunosorbent Assay; Fiber Optic Technology; Herbaspirillum; Herbaspirillum - cytology; Herbaspirillum - immunology; Herbaspirillum - isolation & purification; Lipopolysaccharide; Phage antibodies
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2019.04.086

A sheep single-chain antibody-fragment library (Griffin.1, UK) was used to obtain miniantibodies to the lipopolysaccharide of Herbaspirillum seropedicae Z78. Using electro-optical analysis and electron microscopy, we recorded a biospecific interaction of antigenic determinants on the cell surface with phage antibodies against the LPS of H. seropedicae Z78 (mini-AbsLPS). Control experiments were run to rule out nonspecific binding of the mini-AbsLPS to cells of Azospirillum brasilense Sp245. Use of the highly specific mini-AbsLPS enabled the lipopolysaccharide of H. seropedicae Z78 to be detected in a mixture of bacterial cells by electro-optical means (analysis time, ∼5 min). This report is the first to show the possibility of rapid detection of Herbaspirillum on the basis of electro-optical analysis coupled with the use of mini-AbsLPS. The results are promising for the development of biosensor-based methods to detect potentially human-harmful prokaryotes whose structures either have not been studied or are absent from commercial databases. [Display omitted] •A sheep single-chain antibody-fragment library was used to obtain phage antibodies to the lipopolysaccharide of H. seropedicae Z78.•By using electro-optical analysis and electron microscopy, a biospecific interaction of the LPS with the phage antibodies was recorded.•Bacterial cell detection is based on the recording of changes in the EO signal before and after cell interaction with specific phage antibodies.•The sensor recorded interactions of Z78 cells with mini-AbsLPS in a mixture of bacterial cells with a detection limit of 104 cells ml−1, in ~5 min.