Ultrasensitive determination of allura red in food samples based on green-emissive carbon nanodots

The accurate analysis of allura red (AR), a kind of synthetic azo dye, has attracted increasing concern due to their high toxicities. In this work, a highly sensitive sensing strategy based on fluorescence carbon nanodots (FCNs) was proposed for AR detection. The AR was found to be effective in quenching the fluorescence of FCNs via multi-mechanism synergistic effects of electrostatic adsorption, dynamic reation and inner filter effect (IFE). The analytical applicability and sentivitity of FCNs for AR detection were evaluated. A good linear relationship in a concentration range of 0.01-10.0 mu mol L(-1)and a detection limit of 23.5 nmol L-1 were obtained. Moreover, the potential real application of the proposed method for AR determination was validated in soft drink, candy and chocolate samples. The results showed good accuracy and precision with recoveries of 97.4-104.8% and relative standard deviations (RSDs) <= 3.58%. This work provided a new insight and an operational access to AR detection in the field of food safety monotoring.

Automated summary

A highly sensitive sensing strategy based on fluorescence carbon nanodots (FCNs) was proposed for accurate analysis of the synthetic azo dye allura red (AR). The results showed that the proposed method had good analytical applicability and sensitivity for AR detection, and also demonstrated good accuracy and precision in the real application for AR determination in soft drink, candy and chocolate samples.