Smartphone-assisted colorimetric and near-infrared ratiometric fluorescent sensor for on-spot detection of H2O2 in food samples

Hydrogen peroxide (H2O2) is closely involved in the fields of food industry. Excessive residual H2O2 in food samples will exert adverse effects on the nutritional value of foods and pose great threat to the health of consumer. Development of a reliable analytical method for on-spot quantitative detection of H2O2 levels in food is of urgent necessity. Here, we presented a colorimetric and near-infrared (NIR) ratiometric fluorescent sensor for on-spot quantitative detection of H2O2 in various food samples. The sensor displayed colorimetric and NIR ratiometric fluorescence dual-signal response to H2O2 with high selectivity and sensitivity. The limits of detection (LOD) was measured to be 23.08 nM (S / N = 3). The sensor has been applied for detecting exogenous and endogenous H2O2 in living cells by fluorescence imaging. Also, the changes of H2O2 level in potato tissue infected by phytophthora infestans has been monitored. Particularly, to achieve on-spot quantitative detection of H2O2 in food samples, a portable and field deployable detection device was rationally developed. The sensor, together with portable detection devices and smartphones, performed on-spot quantitative detection of H2O2 in chicken wings and milk through dual signal outputs of colorimetry and fluorescence. We anticipate that the analytical method developed here could be served as convenient tool for on-spot quantitative detection of H2O2 in different foods in near future.