A near-infrared nitrogen and sulfur co-doped carbon dot (N,S-CD)-based ratiometric fluorescent probe is proposed that is synthesized via hydrothermal approach using glutathione and formamide as precursor for sensing and imaging of Zn2+. The prepared N,S-CDs facilitate binding with Zn2+ owing to N and S atom doping. The ratio (I650/I680) of fluorescence intensity at 650 nm and 680 nm increased with the concentrations of Zn2+ when the excitation wavelength was 415 nm. The linearity range was 0.01 to 1.0 μM Zn2+with a detection limit of 5.0 nM Zn2+. The proposed probe was applied to label-free monitoring of Zn2+ in real samples and fluorescent imaging of Zn2+ in living cells, which confirmed its promising applications.
Keywords: Cell imaging; Near-infrared N,S-CDs; Ratiometric fluorescent probe; Zn2+ detection.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.