One-step microwave synthesis of N,S co-doped carbon dots from 1,6-hexanediamine dihydrochloride for cell imaging and ion detection

Abstract

As a new member of the fluorescent carbon nanomaterial family, carbon dots (CDs) not only have outstanding photoluminescence properties and small size characteristics, but also contain favourable low cytotoxicity and biocompatibility, which could be the best choice to detect of ions to replace quantum dots for ions detection. Here, the N,S co-doped carbon dots (N/S-CDs) was synthesized by one-step microwave using 1,6-hexanediamine dihydrochloride and dimethyl sulfoxide as precursors, and their morphology and structure were characterized by TEM, XRD, XPS and FTIR. The optimal emission wavelength of the CDs was 512 nm with green fluorescence, and was red-shifted gradually as the excitation wavelength aggrandized. The synthesized CDs owned a well quantum yield of 24 %. It was further applied for the detection of MnO₄^- and Cr₂O₇^2- with an excellent detection limit of 0.34 μM and 0.23μM, respectively. Cr₂O₇^2- did not influence the N/S-CDs PL response of MnO₄^- in the presence of excessive Pb²⁺. Moreover, the obtained N/S-CDs demonstrated preeminent biocompatibility and could be resoundingly applied for cellular imaging.

Keywords: Carbon dots; Cell imaging; Ion detection; Microwave synthesis.