FOOD SCIENCE ›› 2019, Vol. 40 ›› Issue (18): 323-328.doi: 10.7506/spkx1002-6630-20190220-120

• Safety Detection • Previous Articles     Next Articles

Rapid Quantitative Detection of Escherichia coli O157:H7 in Milk Based on Catalytic Activity of Cobalt-Based Metal Organic Framework (ZIF-67)

WANG Shujuan, LIU Cheng, FANG Shuiqin, TIAN Yachen, DONG Qingli, WANG Xiang, XU Dongpo, LIU Qing,   

  1. (1. School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; 2. Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266071, China)
  • Online:2019-09-25 Published:2019-09-23

Abstract: The aim of this study was to establish a new method for the rapid quantitative detection of Escherichia coli O157:H7 (E. coli O157:H7) in milk samples based on the catalytic activity of metal-organic framework. A cobalt-based metal organic framework (ZIF-67) was synthesized by using 2-methylimidazole and cobalt chloride hexahydrate as starting materials with Bola amphiphilic surfactant as solvent. The catalytic performance of ZIF-67 was studied. It was found that ZIF-67 had similar catalytic activity to horseradish peroxidase (HRP) and could catalyze the chromogenic reaction of 3,3’,5,5’-tetramethylbenzidine (TMB) in the absence of hydrogen peroxide (H2O2). Based on this, we established a method for indirect detection of E. coli O157:H7 in milk by specific enrichment with magnetic microspheres and subsequent detection of ZIF-67 combined with the target. The detection range of this method was 17–1.7 × 108 CFU/mL, and the detection limit (LOD) was 17 CFU/mL. The detection took 1 h. This method could detect E. coli O157:H7 in milk quickly and simply with high sensitivity and selectivity. It has great potential for application in rapid screening of foodborne pathogens.

Key words: cobalt-based metal organic framework (ZIF-67), peroxidase-like activity, chromogenic reaction, double antibody sandwich method, Escherichia coli O157:H7

CLC Number: