In this work, we present a novel microbial biosensor for Salmonella based on impedance spectrometry by using isolated antibodies against a specific bacterial strain from human serum. Anti-Salmonella (or BL21(DE3)) antibodies were isolated from human serum using S. enteritidis (or BL21(DE3)) and the mutant strain ClearColi. After the purification steps, the purification yield of the antibodies was calculated to be 0.2 %. From the FACS analysis, the isolated anti-Salmonella antibodies were estimated to have more than 6-fold higher binding affinity for S. enteritidis compared to antibodies against other kinds of Gram-negative bacterial strains, including HB101, ClearColi, JM110, DH5α, and BL21(DE3). Finally, the anti-Salmonella antibodies isolated herein were used for bacterial detection using electrochemical biosensors based on impedance spectrometry and the Rct value of the antibodies was estimated for S. enteritidis from the Nyquist plot. The limit of detection of the isolated anti-Salmonella antibodies was estimated to be 1.0 × 103 cells/mL for S. enteritidis and 1.0 × 106 cells/mL for BL21(DE3), respectively.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea [grant number: NRF- 2020R1A2B5B01002187 and NRF- 2020R1A5A101913111 ].
All Science Journal Classification (ASJC) codes
- Applied Microbiology and Biotechnology