The extensive use of hypochlorite (ClO − ) as oxidant and bleach has drawn serious concern due to their adverse environment and biological impact. Herein, a novel fluorescence probe composite material based on MAPbBr 3 @ZIF-8 was prepared by agitation method in room temperature , using lead bromide, armour ammonia bromine, 2-methylimidazole and zinc acetate as precursors. MAPbBr 3 @ZIF-8 composites exhibited remarkable stability in NaCl aqueous solution and UV lamp. Thus, the MAPbBr 3 @ZIF-8 composites were successfully used as a fluorescence probe for detection of ClO − via electron transfer and dynamic quenching mechanism. The fluorescence probe can detect ClO − in water with high selectivity even existed other anions (HCO 3 − , SO 4 2− , Cl − , SiO 3 2− , CO 3 2− , NO 3 − , HSO 3 − ). Meanwhile, the response time of the MAPbBr 3 @ZIF-8 probe could be obtained to less than 40 s. The detection limit and quenching constant were calculated as 31.9 nM and 0.141 µM −1 . Furthermore, the fluorescence probe sensor showed excellent stability in natural environment with 94.6%-100.6% recovery rates. The fluorescence probe based MAPbBr 3 @ZIF-8 composites in this study is promising for detecting ClO − anion in water.
Anqi Sun,Shuo Qi,Yu Li,Yiyao Wu,Yin Zhang,Zhouping Wang
Sensitive and selective determination of azlocillin (Azl) is of great significance to food safety and human health as it is recognized as the most prevalently utilized β-lactam antibiotics. Herein, we develop a highly sensitive fluorescence aptasensor selective, and sensitive, determination of Azl in food samples. Initially, the aptamer A-58 with the highest affinity(K d = 64.5 ± 7.2 nM)was obtained by means of truncation. Subsequently, a highly stable aqueous dispersed perovskite nanocrystal MAPbBr 3 @ZIF-8 was synthesized and used as a fluorescent marker in aptasensors. The aptasensor was constructed by using MAPbBr 3 @ZIF-8 as the fluorescence signal source, aptamers as the specific recognition molecules, and AuNPs as a quenching agent. This design integrates the excellent optical properties of perovskite, the fluorescence quenching ability of AuNPs and the specificity of aptamer, exhibiting great promising for trace analysis of Azl in food samples. Under the optimal experimental conditions, the linear detection range of the developed aptasensor method spans from 0.1 to 100 ng/mL, with a detection limit of 0.025 ng/mL. The developed MAPbBr 3 @ZIF-8 based aptasensor has been effectively utilized for the quantification of azlocillin in milk, demonstrating significant potential in the realm of antibiotic detection.
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