Synthesis of carbon quantum dots with green luminescence from potato starch

Abstract

Water-soluble carbon quantum dots (CQDs) are synthesized via an acid assisted ultrasonic route using the biomass carbon precursor of potato starch as the raw material. Results from various characterization methods including TEM, XRD, XPS, Raman spectroscopy and FTIR spectroscopy indicate that monodispersed CQDs with a mean diameter of about 3–5 nm and abundant oxygen-containing groups have been prepared. The photoluminescence performance of the CQDs has been investigated and the results demonstrate that the CQDs exhibit strongly green luminescence, with excitation wavelength-independent, pH-sensitive and ionic strength-dependent luminescence properties. In addition, it has been demonstrated that the CQDs can serve as a very effective fluorescent probe for the selective and sensitive detection of zinc ions in aqueous solution. Hopefully, the synthesized CQDs can find potential applications in pH sensors, bio-imaging, and photocatalysis related areas.