Adenine-derived carbon dots for the chemosensing of hypochlorite based on fluorescence enhancement

• Carbon dots were made from nitrogen-rich adenine via simple hydrothermal strategy. • The sensing mechanism of carbon dots was based on aggregation-induced enhanced emission (AIEE). • Carbon dots can efficiently detect and quantify ClO − in real water samples. A novel fluorescent chemosensing strategy on the detection and determination of hypochlorite (ClO − ) based on fluorescence enhancement was reported. In this work, nitrogen-doped carbon dots (N-CDs) were prepared via one-step hydrothermal conversion of nitrogen-rich adenine and ethylenediamine. The N-CDs solution showed excitation-dependent characteristic and displayed green fluorescence (535 nm) when excited by blue light (480 nm). The fluorescence intensity was linearly enhanced with the concentration of ClO − increasing in the range of 0.01–1 mM, and the limit of detection was calculated to be 0.82 μM. Other than the common oxidation of the N-CDs surface by ClO − , spectra change stemmed mainly from aggregation-induced enhanced emission (AIEE), including π-π staking and J-aggregation, which together induced red-shift absorption band and effective fluorescence enhancement. Based on the good sensitivity to ClO − , the N-CDs probe also underwent real sample assay and gave relatively reliable recoveries of ClO − contained in various water samples. In addition, the N-CDs showed excellent anti-interference in the selectivity test and exhibited good stability in complex solution environment with different pH values or ion strengths. In view of the results, the N-CDs sensing probe has impressive sensitivity and selectivity on ClO − determination and possesses good potential on bioimaging applications.