Detection of cholera toxin with surface plasmon field-enhanced fluorescent spectroscopy

Seherler S., Bozdogan A., Özal Ildeniz T. A., Kök F. N., Sakir I. A.

BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY, vol.69, no.4, pp.1557-1566, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 69 Issue: 4
  • Publication Date: 2022
  • Doi Number: 10.1002/bab.2227
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Applied Science & Technology Source, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Compendex, Computer & Applied Sciences, EMBASE, Environment Index, Food Science & Technology Abstracts, INSPEC, MEDLINE, Veterinary Science Database
  • Page Numbers: pp.1557-1566
  • Keywords: antibody, biosensor, cholera toxin, environmental biotechnology, immobilization, surface plasmon resonance (SPR), surface plasmon field-enhanced fluorescent spectroscopy (SPFS), QUARTZ-CRYSTAL MICROBALANCE, VIBRIO-CHOLERAE, SENSITIVE DETECTION, RAPID DETECTION, FOOD SAFETY, RESONANCE, BIOSENSOR, WATER, IMMUNOSENSOR, PATHOGENS
  • Istanbul Technical University Affiliated: Yes


In this work, a biosensor based on surface plasmon field-enhanced florescence spectroscopy (SPFS) method was successfully constructed to detect the truncated form of cholera toxin, that is, its beta subunit (CTX-B). CTX-B is a relatively small molecule (12 kDa) and it was chosen as model analyte for the detection of protein toxins originated from waterborne pathogens. Recognition layer was prepared on gold-coated LaSFN9 glasses modified with 11-mercaptoundecanoic acid (11-MUA). Biotin-conjugated anti-CTX-B polyclonal antibody (B-Ab) was immobilized on streptavidin (SA) layer constructed on the 11-MUA-modified surface. CTX-B amount was determined with direct assay using B-Ab in surface plasmon resonance (SPR) mode and with sandwich assay in SPFS mode using Cy5-conjugated anti-CTX-B polyclonal antibody. Minimum detected CTX-B concentrations were 10 and 0.01 mu g/ml with SPR and SPFS, respectively, showing the sensitivity of the SPFS system over the conventional one. The detection was done in 2-6 h, which was faster than both culture and polymerase chain reaction (PCR)-based methods. Stability tests were performed with SA-coated sensors (excluding B-Ab). In this form, the layer was stable after 30 days of storage in phosphate-buffered saline (PBS; 0.01 M, pH = 7.4) at +4 degrees C. B-Ab layer was formed immediately on them before each measurement.