Microwave-assisted synthesis of green fluorescent copper nanoclusters: a novel approach for sensing of hydroxyl radicals and pyrophosphate ions <i>via</i> a "turn-off-on" mechanism

초록

In the present work, an off-on fluorescent probe based on green light-emitting coffee-trypsin-CuNCs (coffee-Tryp-CuNCs) is developed for the quick, accurate, and targeted detection of (OH)-O-center dot and pyrophosphate ions (P2O74-, PPi). Coffee-Tryp-CuNCs with minimal toxicity and optimal stability were generated by employing a simple and environmentally friendly approach. The fluorescent emission peak of the coffee-Tryp-CuNCs was found to be at 515 nm upon excitation at 430 nm. Hydroxyl radicals ((OH)-O-center dot) selectively decrease the fluorescence intensity of coffee-Tryp-CuNCs, and the quenched fluorescence is recovered in the presence of PPi by a turn-on mechanism. The designed probe exhibits a pH dependent response as a highly acidic environment results in the destruction of the CuNCs due to aggregation. Moreover, the coffee-Tryp-CuNCs were unable to detect (OH)-O-center dot in acidic conditions (pH 2-6) but as soon as PPi was added to coffee-Tryp-CuNCs-(OH)-O-center dot the fluorescence emission intensity recovers indicating that the pH of the solution affects the detection of (OH)-O-center dot and PPi. Under the optimized conditions, the detection limits (LOD) for the determination of (OH)-O-center dot and PPi are estimated as 1.03 mu M and 0.68 nM. The probe was used satisfactorily for quantifying (OH)-O-center dot in tap and industrial water samples.

키워드