Because anthrax spores are highly lethal to humans and animals as well as potential biological warfare agents, there is a great need for rapid, sensitive, and selective quantification of dipicolinic acid (DPA) as a biomarker for anthrax spores. Herein, we prepared a novel lanthanide-doped nanoprobe by coordination of Tb3+ ions with tannic acid (TA)-coated zeolitic imidazolate frameworks-8 (ZIF-8) (ZIF-8@Tb–TA). The proposed assay was derived from the unsaturated coordination of Tb3+ ions. In the presence of DPA, Tb3+ ions could be sensitized to emit inherent luminescence due to the energy transfer after coordination with DPA. The results illustrated that ZIF-8@Tb–TA could be used as a sensitive nanoprobe for detecting DPA with a broad linear range (0 μM to 12.0 μM), and the limit of detection (LOD) was 12.3 nM. Moreover, the specific recognition ability of DPA by ZIF-8@Tb–TA was much better than that of other interfering molecules. This study proposed a new strategy to establish lanthanide-functionalized nanoprobes for highly selective and sensitive detection of DPA.
In this paper, a series of Ba2GaB4O9Cl:Ce 3+ ,Tb 3+ phosphors were synthesized by the conventional high-temperature solid-state reaction. The incorporation of Ce 3+ ions as sensitizers significantly enhances the absorption and luminescence intensity of Tb 3+ ions in the Ba 2 GaB 4 O 9 Cl phosphor. The energy transfer from Ce 3+ to Tb 3+ occurs through the electric quadrupole-quadrupole interaction, with an energy transfer efficiency of 48 %. The internal quantum efficiency of Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ phosphor is 39.95 % upon 316 nm excitation. At 423 K, the emission intensity of Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ can keep 53.28 % of its initial value at room temperature. All these results indicate that the Ba 2 GaB 4 O 9 Cl:Ce 3+ ,Tb 3+ phosphor has potential application for white LED.
Teng Zhang,Ruchun Zhao,Heyi Yang,Fangyi Zhao,Qinan Mao,Meijiao Liu,Jiasong Zhong
The security level of traditional long persistent luminescence (LPL) phosphor with a single adjustable decay time is increasingly insufficient to meet the demands of a rapidly advancing society, resulting in significant losses for individuals and corporations. Therefore, exploring a phosphor with a two-model of adjustable decay time and afterglow color is meaningful for advanced information encryption and anti-counterfeiting. Here, we propose a simple and efficient strategy to regulate the trap type and concentration in high defect tolerance matrix CaGa 4 O 7 (CGO), achieving tunable emission color, afterglow color and decay time. At first, we introduce the rare earth ions Tb 3+ to generate the new defects, and then substitute Ca 2+ with Zn 2+ in CGO:Tb 3+ (CZGO:Tb 3+ ) phosphors to increase the inherent defects concentration, thereby greatly increasing the number of band electrons trapped by the defects and improving their LPL performance. Owing to the lattice distortion, its luminescence performance is increased by 6.09 times. It is worth noting that CZGO:Tb 3+ phosphor has a variety of emission modes over time, so it has great potential in information anti-counterfeiting and encryption applications.
危险品化学品经营许可证（带存储）