Smartphone-based label-free ratiometric fluorescence detection of sertraline and glutathione based on the use of orange-emission carbon dots

The novel label-free ratiometric fluorescent sensing platform was constructed for fluorescence and smartphone dual-mode determination of sertraline (Ser) and glutathione (GSH) based on orange emission carbon dots (O-CDs). The O-CDs was prepared using neutral red and polyethyleneimine as raw materials via a facile one-pot hydrothermal treatment. As the concentration of Ser increases, a new emission peak appears at the carbon dot at 533 nm, and the intensity of the emission peak at 593 nm does not vary, which is accompanied by the evident photoluminescence of the solution from orange to green. Besides, the ratio fluorescence of [email protected] can be effectively restored by introducing GSH, and the photoluminescence of the N-CDs solution changes from green to orange. Inspired by the fact, a smartphone sensing platform was developed for online analysis of Ser and GSH content. Moreover, the O-CDs have been favorably exploited for label-free ratiometric determination of Ser and GSH in PC-12 cells owing to its lower toxicity and excellent biocompatibility. Interestingly, the O-CDs can be used to manufacture O-CDs/starch photoluminescence powders and O-CDs/PVA photoluminescence flexible films. These findings may broaden the path for the development of orange emission carbon-based nanomaterials and their applications for ratiometric sensing, smartphone sensing, cellular imaging, and photovoltaic materials.