Siyang Deng,Huan Liu,Chunhui Zhang,Xinting Yang,Christophe Blecker
Nitrite (NO 2 − ) is widely present in meat products as a vital food preservative, while excessive nitrite is a serious carcinogen to human beings, developing a sensitive and selective nitrite detection method is of great significance for food safety. Herein, a novel luminescent metal organic framework (LMOF) (Rh6G@MOF-5) is prepared through a facile one-pot synthesis as a fluorescent turn-off sensor for NO 2 − determination. Upon exposure to NO 2 − , significant fluorescence intensity decreases linearly along with NO 2 − concentration in the range of 0–200 μmol/L and the detection limit is estimated to be 0.2 μmol/L. The developed nanocomposite has been shown to be an ultrasensitive and selective nanoprobe for detecting NO 2 − in meat products, with recoveries ranging from 96.1% to 103.2% with the RSDs less than 4%. Rh6G@MOF-5 nanoprobe offers insight into the fabrication of MOF-based sensors with low cost and convenient operation in analyte detection field.
Han Li,Donghui Wang,Wei Liu,Zhan Ma,Dingnan Wang,Yang Li,Weiwei Huan,Yiming Zhang
The development of high-performance specific sensors is promising for the rapid detection of harmful residues in animal-derived foods. Recently, luminescent metal-organic framework/molecularly imprinted polymer (LMOF/MIP) materials have been developed as ideal candidates for the analysis of harmful residues. Here, we reported a simple fabrication protocol of paper-based chip through in-situ growth of LMOF on a negatively charged modified filter paper, a paper-based molecularly imprinting layer (FP@BA-Eu@MIP) was thereafter successfully prepared via the boronate affinity-based controllable oriented surface imprinting strategy. The paper-based chips obtained were used to construct a rapid test strip of tetracycline (TC). After addition of TC, significant fluorescence changes on the surface of the FP@BA-Eu@MIP paper-based chip could be observed from blue to red via inner filter effect and photo-induced electron transfer under the excitation of 360 nm. The adsorption kinetics was explored in detail. The presented strip exhibited satisfied selectiveness and sensitivity with a limit of detection of 8.47 μg L −1 for TC. It was confirmed that LMOF/MIP as a biomimetic recognition module can play a crucial role in enrichment and fluorescence response. This study provided a real application case for an in-situ fabricated fluorescence paper-based chip in rapidly detecting harmful residues.