Fluorine-doped carbon quantum dots with deep-red emission for hypochlorite determination and cancer cell imaging

As a type of new carbon-based nanomaterials, carbon dots (CDs) possess exceptional optical properties, making them highly desirable for use in fluorescent sensors. However, the CDs with deep-red (DR) or near-infrared (NIR) emission have rarely been reported. In this work, we prepared deep-red emissive fluorine-doped carbon quantum dots (F-CDs) by introducing a precursor simultaneously containing fluorine and amidogen. The synergistic effect of nitrogen doping and D-π-A pattern production contributed to the maximum emission of F-CDs at 636 nm with an absolute quantum yield of 36.00% ± 0.68%. Moreover, we designed an F-CDs-based fluorescence assay to determine the content of hypochlorite (ClO−), with a limit of detection (LOD) as low as 15.4 nmol/L, indicating the high sensitivity of F-CDs to ClO−. In real samples, the F-CDs-based fluorescent sensor exhibited excellent sensitivity and selectivity in the detection of ClO−, with an error below 2%, suggesting their great potential in daily life. In cancer cell imaging, the F-CDs not only demonstrated high sensitivity to ClO− but also exhibited excellent mitochondria targeting, as evidenced by the high Pearson's correlation coefficient (PCC) of 0.93 in colocalization analysis. The work presented here suggests the great potential of replacing commercial dyes with F-CDs for highly specific mitochondria labeling and cell imaging.