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Abstract
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Herein, high performance peroxidase-like activity of zinc and cobalt bi-metal metal-organic framework (ZnCo
MOF) is reported and applied for the sensitive measurement of atropine. ZnCo MOF was synthesized by the
reaction of 2-methylimidazole with Zn and Co (II) cations in aqueous media. The colorimetric and fluorometric
experiments were applied to investigate the catalytic activity of obtained MOF, using o-phenylenediamine (OPD)
and terephthalic acid (TA) peroxidase substrates, respectively. The results demonstrated the more efficient
mimetic behavior of ZnCo MOF compared with common Zn or Co MOFs. Besides, it was found that atropine
hindered the catalytic action of ZnCo MOF and this effect was intensified by increasing the atropine concentration.
So, it was considered to design a sensitive analytical assay for atropine detection. To assure a high
specific recognition, molecularly imprinted polymer (MIP)-based extraction using magnetic graphene oxide
supports was applied to extract atropine before its determination. The combination between the high specific
extraction and great catalytic activity of ZnCo MOF led to the ultrasensitive and reliable determination of
atropine. The best linear range of calibration graph was achieved using fluorometric detection system for
0.1–45 ng mL−1 atropine concentrations, and detection limit (3Sb/m) was 27 pg mL−1. The relative standard
deviations (RSD %) for the determination of 1, and 10 ng mL−1 atropine (n=5) were 2.13% and 3.08%, respectively.
The explained fluorometric assay was examined for the measurement of atropine in biological fluids
(Recoveries were in the range of 95.90–103.57%), and the results were validated by an official method.
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