Fluorescent Carbon Dots from Bamboo Stem Waste: Synthesis, Characterization, and Inkjet Printing

Abstract

Among the various anti-counterfeiting solutions, fluorescent compounds gained attention as challenging to copy solutions because of astute technological improvements. However, fluorescent compound usage in counterfeit detection is limited due to high price of rare earth metals, the low photostability of pigments or organic dyes, and the long-term toxicity of conventional semiconductor quantum dots. Herein lies the value of carbon dot, a very stable, reasonably priced, and environmentally friendly material with intriguing features. In this work the development of blue fluorescent, N-doped carbon dots (NCD) from waste bamboo stem cuttings via hydrothermal route is presented as an environmentally friendly approach to reduce the risk of toxic gas evolution from burning of bamboo waste. The carbon dot's practical application in anti-counterfeit printing was ascertained by comprehending it's superior properties, such as high water solubility, eco-friendliness, dazzling fluorescence, and surface functionalization through various characterization techniques. Inkjet printing of the designs on paper substrate using the aqueous NCD ink displayed reversible encryption-decryption ability through variation of pH. The development paves the way for value-added utilization of waste bamboo cuttings in fluorescent ink production.