Rapid, ultrasensitive and non-enzyme electrochemiluminescence detection of hydrogen peroxide in food based on the ssDNA/g-C3N4 nanosheets hybrid

• Free from complicated sample pretreatment. • Non-enzyme electrochemiluminescent (ECL) biosensor based on single-stranded DNA (ssDNA)/g-C 3 N 4 NS hybrid. • Ultra-sensitive hydrogen peroxide detection for milk samples. Hydrogen peroxide (H 2 O 2 ) is usually used as a fungicide in food, it is carcinogenic, accelerates aging or inducing toxic effects such as cardiovascular disease. Herein, to meet the demand for effective and fast detection of H 2 O 2 in food, a novel non-enzymatic electrochemiluminescence (ECL) sensor based on single-stranded DNA (ssDNA)/g-C 3 N 4 nanosheets (NS) was established. The ssDNA/g-C 3 N 4 NS hybrid was prepared by simple mixing g-C 3 N 4 NS and ssDNA solution together. The prepared ssDNA/g-C 3 N 4 NS exhibited improved peroxidase-like activity and was modified on a glassy carbon electrode to catalyze the ECL reaction of luminol-H 2 O 2 to amplify the luminescence signal. Under the optimized conditions, the proposed sensor exhibits high sensitivity with a limit of detection (LOD) as low as 33 aM H 2 O 2 , which is much lower than the vast majority of reported methods. This method enables the reliable responding to H 2 O 2 from the milk samples within 1 min.