Point-of-care colorimetric biosensor for H2O2 and glucose detection utilizing the peroxidase-like activity of 2D bimetallic metal organic framework nanosheets

Abstract

Background

The applications of natural enzymes are vast, limited only by their protein nature. Therefore, the development of artificial enzyme mimetics, nanozymes, which are stable and have improved activity, has become indispensable for biomedical and diagnostic purposes. Nanozymes have developed into an emergent topic combining nanotechnology and biology due to their vast range of potential uses. In comparison to natural peroxidase, peroxidase-imitating nanozymes have distinct benefits in terms of high stability and low cost for applications in bioanalysis and environmental remediation. The use of metal-organic framework nanoparticles has exhibited enhanced catalytic and enzymatic performance.

Results

In the current work, we present a strategy for synthesizing 2D Ni/Co MOF nanoparticles that have been anchored onto carboxymethyl cellulose (CMC). The resulting composite (Ni/Co-MOF@CMC) 2D nanosheets exhibit a high surface area and abundant catalytic sites, greatly amplifying their peroxidase-like catalytic performance. Additionally, these 2D bimetallic MOFs mimic the peroxidase activity, demonstrated by the distinctive yellow colour upon the oxidation of o-Phenylenediamine (OPD) by hydrogen peroxide. This newly synthesized 2D bimetallic MOF provides a straightforward, simple, selective, and sensitive colorimetric analysis technique for the determination of hydrogen peroxide and glucose. H₂O₂ could be efficiently detected with a linear range of 10 μM–800 μM and a lower detection limit of 3.28 μM. With the potential to detect minute glucose concentrations as low as 200 μM within a linear range of 200 μM–600 μM.

Significance and novelty

This work demonstrates the significant novelty of applying an RGB colour sensor (TCS34725) for the quantitative measurement of H₂O₂ and glucose which holds great potential as a point-of-care platform for diabetic patients. Consequently, our approach broadens the use of MOFs in biosensing and presents a viable substitute for affordable, and easily accessible diabetes monitoring. These 2D bimetallic MOFs are promising materials for glucose detection applications, expanding the utility of MOFs to include biosensor applications.