Prussian blue modified metal–organic framework MIL-101(Fe) with intrinsic peroxidase-like catalytic activity as a colorimetric biosensing platform

Abstract

Nanosized porous PB/MIL-101(Fe) was facilely prepared by growing Prussian blue (PB) on MIL-101(Fe). It has more active sites and pores for peroxidase substrates and gives a simple, sensitive colorimetric assay to detect H2O2 and glucose.

Metal-organic frameworks as biosensors for luminescence-based detection and imaging

“…Another MOF, MIL-101(Fe), possesses several advantageous material properties for sensing applications, including large pore sizes (2.9 and 3.4 nm, with windows of 1.2 and 1.6 nm) [ 72 ], high surface area per unit mass (5500 m 2 g −1 ) [ 73 ], stability in air and water [ 42 ], accessible exposed metal sites, and organic ligands for functionalization. Furthermore, it has a small band gap that enables excitation by visible light; yet, despite these characteristics, MIL-101(Fe) has not been as widely explored as a peroxidase-mimic for colorimetric biosensing.…”

“…Cui et al [ 42 ] demonstrated the ability of their PB/MIL-101(Fe) MOFs to catalyse the oxidation of TMB, OPD and 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonate) in the presence of H 2 O 2 , which formed reactive OH• radicals that further react to produce a visible colour change. Kinetics were shown to be linear with respect to H 2 O 2 concentration in the range of 2.40–100 mM, with a detection limit of 0.15 mM, comparable with other MOFs [ 60 , 78 ].…”

“…These reagents adsorbed to iron atoms and carboxyl groups, which compromised catalytic activity as a result of blocked active sites. In particular, the addition of FA enabled colorimetric detection of cancer cells with upregulated FA receptors (MCF-7), as the PB/MIL-101(Fe)-FA bound much more strongly to the cell surface than PB/MIL-101(Fe) without FA, and showed increased absorbance with the number of MCF-7 cells [ 42 ].…”

“…We split our analysis into two key areas: quantitative and qualitative sensing ( figure 1 ). Quantitative sensing involves the selective interaction of an analyte with a MOF and the use of inherent or post-synthetically imparted MOF luminescence for visual observation of the sensing event and direct measurement in solution or in vitro [ 42 ]. Mechanical and electrical schemes have not been included in this review so as to focus on the luminescence element of biosensing.…”

Molecular imprinting on PtPd nanoflowers for selective recognition and determination of hydrogen peroxide and glucose

“…Nanozymes, a nanomaterial with enzyme-like activity, are attracting more and more attention thanks to their outstanding properties. [1][2][3] To date, various nanozymes, including metalorganic frameworks (MOFs), [4][5][6][7] metal nanoparticles, 8 oxidized metal nanoparticles 9,10 and some other nanomaterials, 11 have been successfully prepared and used as enzyme mimics for catalytic applications. 2 As one of the enzyme mimics, Pt nanoparticles have been demonstrated to exhibit versatile catalytic activity like peroxidase, catalase and superoxide dismutase.…”