A strong green fluorescent nanoprobe for highly sensitive and selective detection of nitrite ions based on phosphorus and nitrogen co-doped carbon quantum dots

Numerous methods including chromatography, chemiluminescence and spectrophotometry have been reported to detect the nitrite ions. Recently, fluorescent carbon quantum dots have drawn more and more attention as effective sensors to small ions or biomolecules. Here, we will present a solvothermal method to prepare phosphorus and nitrogen codoped carbon quantum dots (PNCQDs) with green-emitting (quantum yield 18.9%). The as-prepared carbon quantum dots exhibit good photostability, low-toxicity and favourable biocompatibility. In addition, the PNCQDs show a high selectivity detection of NO2− with a linear relationship between 10 nM and 90 nM and a detection limit as low as 3.3 nM. Meanwhile, the PNCQDs as fluorescent nanoprobes for detection of nitrite were efficient applied in HeLa cells imaging and potential applications in biologically related study.