Anti-fake label and security identification system based on multiple luminescent quantum dots

Recent advancements in nanomaterials have produced a new class of fluorescent labels based on the semiconductor quantum dots. The emission wavelength of quantum dots can be continuously tuned by changing the particle size or component, and a single light source can be used for simultaneous excitation of all dots with different band gaps. High-quality dots are also highly stable against photobleaching and have narrow, symmetric emission spectra. These novel optical properties render quantum dots ideal fluorophores for ultrasensitive, multicolor, and multiplexing applications in anti-fake label and security identification. In the past research, we have successfully synthesized Cd
_x
Zn
_1-x
Se quantum dots with their fluorescent emission from 500 to 600 nm (from green, yellow, orange to red). Here, we achieved the multicolor optical coding for engineering assays through coating different-colored quantum dots onto the anti-fake label, which further resulting in a new security identification system. The predominant fluorescent properties of Cd
_x
Zn
_1-x
Se quantum dots made the system nearly perfect, such as ultrasensitive, quite informative as well as safely confidential. Furthermore, we designed the flow chat of hardware with prototype read-out system. The multiple luminescent Cd
_x
Zn
_1-x
Se quantum dots based anti-fake system can be applied to supermarket labeling, military security and object identification.