Luminescent properties of carbon dots originated from pine pollen for anti-counterfeiting application

A facile and green approach for the synthesis of luminescent carbon dots (CDs) was studied using pine pollen as raw material. The as-synthesized CDs exhibited hydrophilic properties and excitation-dependent emission owing to the presence of various ligands in the CDs. The luminescence mechanism of the CDs was studied via ultraviolet–visible (UV–vis) absorption and photoluminescence spectroscopy. Under 354 nm excitation, the CDs showed a maximum emission intensity at 438 nm, which makes it a suitable luminescent material for anti-counterfeiting applications. Based on these results, the development of the CDs through inkjet printing for anti-counterfeiting applications was studied. The printed patterns emitted blue light under UV excitation with a quick dry speed, high resolution, and excellent covertness under daylight. These new fluorescent CDs are promising candidates for luminescent materials used in anti-counterfeiting applications.