A colorimetric immunoassay for determination of Escherichia coli O157:H7 based on oxidase-like activity of cobalt-based
- PDF / 2,117,713 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 1 Downloads / 273 Views
ORIGINAL PAPER
A colorimetric immunoassay for determination of Escherichia coli O157:H7 based on oxidase-like activity of cobalt-based zeolitic imidazolate framework Shujuan Wang 1 & Dongpo Xu 1 & Chengchao Ding 1 & Yachen Tian 1 & Kangjie Ge 1 & Liang Guo 1 & Jie Li 1 & Qingli Dong 1 & Yong Huang 2 & Qing Liu 1,3 Received: 15 September 2019 / Accepted: 23 June 2020 # Springer-Verlag GmbH Austria, part of Springer Nature 2020
Abstract Cobalt-based zeolitic imidazolate framework nanosheets (ZIF-67) with oxidase-like catalytic activities as an immunoprobe were employed to enhance the sensitivity of an immunoassay. ZIF-67 was synthesized via the solvothermal method using 2methylimidazole and cobalt dichloride as substrates. A colorimetric immunoassay for Escherichia coli (E. coli) O157:H7 was designed. Preparation of the immunoprobe involved self-polymerized dopamine being applied for the surface modification of ZIF-67 nanosheets in order to bind to the antibody, which was used to identify E. coli O157:H7. ZIF-67 catalyze the oxidation of 3,3′,5,5′-tetramethylbiphenyl (TMB) and produced a color change from colorless to blue. Upon reaction termination, the absorbance was measured at 450 nm. By combining ZIF-67@PDA catalyzed chromogenic reaction with antibody recognition and magnetic separation, the limit of determination is 12 CFU mL−1 and the linear range is 30 to 3.0 × 108 CFU mL−1. The proposed colorimetric immunoassay was successfully utilized to detect E. coli O157:H7 of spiked food samples. Keywords Colorimetric immunoassay . ZIF-67·dopamine self-polymerized . Antibody recognition . Escherichia coli O157:H7
Introduction Escherichia coli O157:H7 (E. coli O157:H7) is one of the most dangerous foodborne pathogens and is sufficient to cause severe illnesses in low numbers [1]. The main methods for rapid detection of such pathogens include Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00604-020-04407-3) contains supplementary material, which is available to authorized users. * Yong Huang [email protected] * Qing Liu [email protected] 1
School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
2
Affiliated Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu University of Traditional Chinese Medicine, Sichuan 611137 Chengdu, China
3
Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People’s Republic of China
conventional culture-based techniques [2], polymerase chain reaction (PCR) [3], and enzyme-linked immunosorbent assay (ELISA) [4]. The conventional methods are the most commonly used but suffer from a laborious and lengthy process [5]. Furthermore, DNA-based methods require professional instrument and operator. Therefore, it is necessary to develop a sensitive and quick method for the determination of E. coli O157:H7, in order to ensure food safety. ELISA is employed in
Data Loading...
