Metal-free auxiliary pyrophosphate detection based on near-infrared carbon dots

Herein, a novel near-infrared nitrogen, sulfur doping carbon dots (N,S-CDs) were prepared and showed super-sensitive response to PPi in water samples, milk, cells and zebrafish. [Display omitted] •A novel near-infrared nitrogen, sulfur doping carbon dots (N,S-CDs) were prepared by using dopamine as carbon source, trace sulfuric acid as sulfur doping material and o-phenylenediamine as nitrogen-doping material.•The obtained probe N,S-CDs exhibited hypersensitive response to PPi with detection limit as 0.15 nM.•Probe N,S-CDs can be used for the detection of PPi in water and milk samples.•Probe N,S-CDs were successfully applied to the imaging of PPi in cells and zebrafish. The excessive use of pyrophosphate (PPi) anions as additives poses a serious threat to human health and the environment. Considering the current status of PPi probes, the development of metal-free auxiliary PPi probes has important applications. In this study, a novel near-infrared nitrogen and sulfur co-doped carbon dots (N,S-CDs) were prepared. The average particle size of N,S-CDs was 2.25 ± 0.32 nm with average height was 3.05 nm. The probe N,S-CDs showed a special response to PPi, and a good linear relationship was obtained with PPi concentrations ranging from 0 to 1 μM, with the limit of detection being 0.22 nM. Tap water and milk were used for practical inspection, and ideal experimental results were acquired. In addition, the probe N,S-CDs also showed good results in biological systems, such as cell and zebrafish experiments.