Microwave-assisted synthesis of N,P-doped carbon dots for fluorescent cell imaging

Nitrogen and phosphorus co-doped carbon dots (N,P-C-dots) were prepared by microwave-assisted thermolysis of N-phosphonomethyl aminodiacetic acid and ethylenediamine. N,P-C-dots exhibit bright blue fluorescence with an emission maximum at 418 nm. Experimental results show that they have uniform dispersion with the average size of 3.3 nm, a fluorescence decay time of 7.8 ns, a quantum yield of 17.5 %, low toxicity, and good stability. All these make them an excellent choice as a fluorescent nanomaterial for use in cellular imaging.