M-phenylenediamine-based color carbon dots open a new chapter in the application of nucleic acid dyes

The performance of nucleic acid dye for staining and labelling nucleic acid molecules directly determines the effectiveness of nucleic acid detection. The widely used traditional nucleic acid dyes pose economic and environmental challenges due to their high price, high toxicity, and long dyeing time. Therefore, we propose the synthesis of m -phenylenediamine carbon dots for use as nucleic acid dye in agarose gel electrophoresis to achieve efficient visualization of DNA and RNA. The prepared carbon dots emit blue, green, yellow, and white fluorescence, diversifying the nucleic acid dye colour selection. We studied the interactions between the carbon dots and ctDNA by Ultraviolet–visible light spectroscopy, Fourier transform infrared spectroscopy and circular dichroism spectroscopy, finding that interaction occurs mainly through groove binding, accompanied by a slight electrostatic interaction. Notably, the sensitivity of the prepared carbon dot nucleic acid dye for nucleic acid detection reached 10 ng/μL comparable to traditional nucleic acid dye sensitivity.