A smartphone-assisted colorimetric and photothermal probe for glutathione detection based on enhanced oxidase-mimic CoFeCe three-atom nanozyme in food

The rational fabrication of point-of-care testing (POCT) featuring simplicity, rapidity, low cost, portability, high sensitivity and accuracy is crucial for maintaining food safety in resource-limited locations and home healthcare but remains challenging. Herein, we report a universal colorimetric-photothermal-smartphone triple-mode sensing platform for POC food-grade glutathione (GSH) detection. This simple sensing platform for GSH detection takes merits of three techniques: commercially available filter paper, thermometer and smartphone via an excellent CoFeCe-mediated oxidase-like activity. This strategy allows CoFeCe three-atom hydroxide to efficiently convert dissolved oxygen into O-2(center dot-) and catalyzes 3, 3 ', 5, 5 '-tertamethylbenzidine (TMB) to generate an oxidized TMB with remarkable color changes and photothermal effect, resulting in a colorimetric-temperature-color triple-mode signal output. The constructed sensor exhibits high sensitivity with a limit of detection of 0.092 mu M for GSH detection. We expect this sensing platform can be easily modified for the determination of GSH in commercial samples with the simple testing strips.

Automated summary

This article describes a universal colorimetric-photothermal-smartphone triple-mode sensing platform for the detection of food-grade glutathione (GSH) at point-of-care. The platform utilizes commercially available filter paper, a thermometer, and a smartphone to achieve high sensitivity and accuracy in GSH detection. The platform shows potential for easily determining GSH in commercial samples using simple testing strips.