On-site colorimetric detection of Salmonella typhimurium based on peroxidase-like activity of aptamer-functionalized 3D covalent organic frameworks embedded with gold nanoparticles

Abstract

Rapid qualitative and quantitative detection of Salmonella typhimurium (S. typhimurium) takes an important role in ensuring food safety. Herein, a colorimetric assay aptasensor for S. typhimurium utilizing intrinsic peroxidase-like activity of Au nanoparticles embedded 3D covalent organic framework and the affinity and specificity of S. typhimurium-aptamer has been explored. This aptasensor can capture the S. typhimurium via the selective binding effect of aptamer, and the catalytically active sites were shielded. As a result, the colorimetric signals of the 3,3’,5,5’-tetramethylbenzidine-H2O2 system were turned off. Under optimum conditions, the aptasensor gave a linear response over the range of 10 to 107 CFU/mL for S. typhimurium. The detection limit of 7 CFU/mL was obtained within 45 min and was effectively applied to detect S. typhimurium in milk and lake water samples with recoveries in the range from 96.4–101.0%. More importantly, combined with a self-developed smartphone-based image analysis system, the proposed aptasensor can be used for point-of-care testing applications

Dual-Readout Ultrasensitive Lateral Flow Immunosensing of Salmonella typhimurium in Dairy Products by Doping Engineering-Powered Nanoheterostructure with Enhanced Photothermal Performance

“…6,7 The incidence rate of S. typhimurium ranks first among Salmonella infections and S. typhimurium can induce nosocomial infection and fulminant food poisoning with a high fatality rate. 8,9 Although antimicrobial intervention is an effective means of addressing bacterial contamination, eggs and milk with Salmonella are identified during foodborne and point source infection. 10,11 The source of pollution can be traced back to the farm through transportation chain.…”

“…typhimurium ranks first among Salmonella infections and S. typhimurium can induce nosocomial infection and fulminant food poisoning with a high fatality rate. , Although antimicrobial intervention is an effective means of addressing bacterial contamination, eggs and milk with Salmonella are identified during foodborne and point source infection. , The source of pollution can be traced back to the farm through transportation chain . Although dependable detection results can be obtained, the detection process is time-consuming and laborious, and that is difficult to fulfill the pressing needs of immediate detection. , Therefore, it is of considerable significance to establish a rapid and accurate specific detection method for the early screening and disease control of S.…”