Dual-emissive persistent luminescent phosphors for multi-mode anti-counterfeiting and ratiometric luminescent aptasensors

Abstract

Persistent luminescent phosphors (PLPs) have attracted much attention in anti-counterfeiting, biosensing and bioimaging due to their characteristic properties of emitting long persistent luminescence (PersL) after excitation ceases. However, most of the PLPs developed so far have only one PersL emission peak, which limits their application in advanced anti-counterfeiting and precise biosensing. Here, a series of dual-emissive Zn₂GeO₄:x% Tb³⁺/y% Bi³⁺ PLPs was prepared by codoping Tb³⁺ ions and Bi³⁺ ions to significantly improve the trap depth and trap density, resulting in a 16.8-fold increase in PersL intensity compared to the Zn₂GeO₄ host. The photoluminescence (PL) color was adjusted to pale blue under 254 nm UV excitation by trap depth engineering, while the PersL color was green, and the PL color under 365 nm UV excitation was yellow. In addition, the PersL intensity was dramatically increased by 16.8 times by co-doping Tb³⁺ and Bi³⁺. Therefore, multi-mode anti-counterfeiting was achieved by multi-stimulus response. Furthermore, the dual-emission band was designed as a ratiometric PersL aptasensor for the detection of mucin 1. The detection linearity ranged from 0.1 to 100 ng mL⁻¹ with a detection limit of 0.036 to 1 ng mL⁻¹. This novel PLP with a dual-emission band expands the application range of PLPs.