Facile microwave-assisted synthesis of casein derived carbon nanodots

Abstract

Belonging to the carbon family, yet standing apart, carbon nanodots are materials with excellent properties. Among them, they are well known for their attractive optical properties. The insight into this outstanding strength has resulted in the discovery of unique design of materials. These nanodots can be prepared via various methods to obtain a good optical response. In our research, we synthesized them using a microwave reactor, which is simple, fast and productive. As a carbon source casein, a low-cost precursor was used. Since this is a protein composed of amino acids, no additional passivation was required. Polyvinylpyrrolidone was used as a stabilizer for the nanodots. The synthesis was carried out at 200 °C for 30 minutes. The color change of the resulting solution to orange brown indicates the formation of carbon nanodots. These nanodots were filtered and dialyzed to be used for further characterizations. The carbon nanodots were spherical with the average size of about 9.7 nm. They showed a strong blue emission in the visible region with an appreciable quantum yield. One of the important characteristics of this method is the availability of reasonably good product yield. The prepared carbon nanodots have potential applications in the field of electrochemistry, optoelectronics and biological imaging. © 2021 TANGER Ltd., Ostrava.