Controlled Synthesis Of Iron Contained Metal-organic Frameworks Fe-MIL-88and Their Applications As Peroxidase Mimic

As a result of alterable framework topologies, tunable pore sizes, high surface areas and unsaturated metal sites, metal-organic frameworks (MOFs) have been importantly used in the fields of gas storage and separation, chemical sensing, catalysis, drug delivery. In this paper, we prepared three kinds of iron involved metal-organic frameworks via a hydrothermal strategy, investigated their peroxidase mimic properties, then further used as new peroxidase mimic and applied in bioanalysis. The main contents are as follows:Nanosized metal-organic framework of Fe-MIL-88NH2as a novel peroxidase mimic and used for colorimetric detection of glucose Nanosized porous metal-organic framework, Fe-MIL-88NH2, was facilely prepared with uniform octahedral shape by the addition of acetic acid, and for the first time demonstrated to possess intrinsic peroxidase mimic activity. Kinetic analysis and electron spin resonance measures indicated that the catalytic behavior was consistent with typical Michaelis-Menten kinetics and follows a ping-pong mechanism. Here, Fe-MIL-88NH2was used to quickly catalyze oxidation of the peroxidase substrate3.3’,5,5’-tetramethylbenzidine (TMB) in the presence of H2O2, producing a color changed product, which provided a simple, sensitive and selective method for the colorimetric detection of glucose. The glucose could be linearly detected in the range from2.0×10-6to3.0×10-4M. More importantly, the colorimetric method could be successfully applied to the determination of glucose in diluted serum samples.Shape-and size-controlled synthesis of metal-organic frameworks Fe-MIL-88and their catalytic activities Using FeCl3·6H2O and terephthalic acid as the reactants. by selectively manipulating the additives such as sodium acetate and glycerol. the Fe-MIL-88MOFs with different shapes including octahedron, spindle and bipyramidal hexagon can be easily and reproducibly obtained. The results of mechanism study indicate that the crystal nucleation rate and orientational growth both play important roles in determining the final shape of the MOFs. Moreover, we have also demonstrated that the Fe-MIL-88has peroxidase mimic properties, and the catalytic activity is greatly dependent on their shapes (bipyramidal hexagon> octahedron> spindle). Owing to the relatively strong catalytic ability of bipyramidal hexagonal Fe-MIL-88, together with its excellent biocompatibility and high porosity, it can be a promising material for storage, delivery and controlled release of important biological molecules and drugs.Controllable preparation of Au@Fe-MIL-88hybrids as highly active peroxidase mimetic for DNA detection Gold nanoparticles (AuNPs) assembled on the surface of Fe-MIL-88was facilely prepared using polyethyleneimine (PEI) molecules as linker. The morphology and crystal structure of the as-prepared hybrids were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX). The resulting hybrid materials of Au@Fe-MIL-88exhibits highly peroxidase mimetic activity. And single-stranded DNA (ss DNA) was easily adsorbed on the surface of Au@Fe-MIL-88hybrids, resulting in the reduce of the peroxidase mimic activity of the hybrids, while it was recovered by the addition of targets DNA. Based on these unique properties, we developed a label-free colorimetric method for DNA hybridization detection. The response to target DNA concentration was linear in the range of30-200nM, with a detection limit of1.28nM. This detection method offers the advantages of simple, cheap, rapid and colorimetric.