Anti-counterfeiting application of fluorescent carbon dots derived from wasted coffee grounds

Abstract Anti-counterfeiting application have various challenges and issue of the luminescent materials which remain to be resolved, such as expensive cost, low synthetic yield and photo-bleaching effect. Since the carbon dots (CDs) derived from wasted organic materials exhibits cheap synthetic cost, noble photo-stability and high synthetic yield, CDs has been paid attention in the anti-counterfeiting field. Herein, we report the synthesis of the fluorescent carbon dots derived from wasted coffee ground and their anti-counterfeiting application. The CDs prepared by hydrothermal synthesis shows uniform morphology with lattice structure. Also, the prepared CDs shows a hydrophilic nature and blue emission under UV excitation. In order to apply a CDs in the anti-counterfeiting field, the resultant CDs ink was printed on various banknotes, by using a simple spray method. The anti-counterfeiting patterns exhibits a blue emission under UV excitation and excellent covertness under daylight with high resolution. These results indicate that the CDs derived from wasted coffee grounds can be applied as a promising luminescent materials in the anti-counterfeiting field.