Disposable syringe-based visual immunotest for pathogenic bacteria based on the catalase mimicking activity of platinum nanoparticle-concanavalin A hybrid nanoflowers.

Disposable syringes were used in a novel point-of-care visual test for detecting pathogenic bacteria (Escherichia coli O157:H7 and Salmonella typhimurium). Hybrid nanoflowers composed of platinum nanoparticles and concanavalin A (Pt-nanoflowers) were prepared through a one-pot reaction and were found to be viable catalase mimics. They catalyze the decomposition of hydrogen peroxide (HO) to generate O.

Hemin-incorporated nanoflowers as enzyme mimics for colorimetric detection of foodborne pathogenic bacteria.

Rapid, sensitive and point-of-care detection of foodborne pathogenic bacteria is essential for food safety. In this study, we found that hemin-concanavalin A hybrid nanoflowers (HCH nanoflowers), as solid mimic peroxidase, could catalyze oxidation of 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) in the presence of HO to a green-colored product. HCH nanoflowers, integrating the essential functions of both biological recognition and signal amplification, meet the requirements of signal labels for colorimetric immunoassay of bacteria.