Ultra-stable anti-counterfeiting materials inspired by water stains

Summary Fluorescent anti-counterfeiting technology has been widely reported for its advantages, such as easy identification and multiple anti-counterfeiting functions. Most of the current fluorescent anti-counterfeiting materials focus on the innovation of anti-counterfeiting mode. However, stability is a prerequisite for applying anti-counterfeiting materials and determining whether a material can be widely used. Inspired by water stains, we report fluorescent nanoparticles that are easily prepared and inkjet printable and have multiple anti-counterfeiting functions and high stability. They are applied successfully to fluorescent anti-counterfeiting. 3D printed microreactors prepared the fluorescent nanoparticles with different emission wavelengths. The nanoparticles adhere firmly to the fibers of paper or cloth under the combined effect of hydrogen bonding and van der Waals forces. The sample paper exhibits good tolerance to extreme environments, such as boiling water, liquid nitrogen, photobleaching, and strong acid. Finally, multiple anti-counterfeiting functions are realized by mobile phones and clustering algorithms.