Vanadium-Doped Porous Cobalt Oxide for Its Superior Peroxidase-like Activity in Simultaneous Total Cholesterol and Glucose Determination in Whole Blood Based on a Simple Two-Dimensional Paper-Based Analytical Device

Abstract

Vanadium-doped porous Co3O4 (V-porous Co3O4) was synthesized via a simple soft-templating method and used as a superior peroxidase mimic for the simultaneous colorimetric determination of glucose and total cholesterol (TC) in whole blood samples on a two-dimensional microfluidic paper-based analytical device (2D-μPAD). The large surface area and the presence of two metals in V-porous Co3O4 contributed to its excellent catalytic activity toward 2,2′-azino-bis­(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 3,3′,5,5′- tetramethylbenzidine (TMB) with Michaelis–Menten constants (K M) of 0.1301 and 0.0141 mM, respectively. The 2D-μPAD was fabricated using simple wax screen-printing and cutting techniques. The colorimetric reactions of both glucose and TC on 2D-μPAD were simultaneously performed by adding a single drop of a whole blood sample on the sample zone made of the LF1 membrane. After the enzymatic reactions, the generated hydrogen peroxide (H2O2) was oxidized by V-porous Co3O4 to produce hydroxy radicals (•OH), inducing ABTS and TMB to generate colored products. The generated H2O2 was proportional to the intensities of the green and blue products of the glucose and TC systems, respectively. The developed 2D-μPAD required a short analysis time (∼5 min) with small volumes of samples (15 μL of whole blood) whereby no sample preparation was needed. Owing to several advantages including simplicity, low cost, long-term stability, and simultaneous readout, the novel V-porous Co3O4 coupled with 2D-μPAD proved to be promising for practical uses as a pioneering portable device for the determination of glucose, TC, and other important biomarkers without the need of technical supports.

Bimetallic Cu–Zn Zeolitic Imidazolate Frameworks as Peroxidase Mimics for the Detection of Hydrogen Peroxide: Electrochemical and Spectrophotometric Evaluation

“…The peroxidase mimicking property of Cu@ZIF-8 is demonstrated using a simple peroxidase assay . In a basic peroxidase assay, HRP enzyme will be oxidized by H 2 O 2 .…”

“…The peroxidase mimicking property of Cu@ZIF-8 is demonstrated using a simple peroxidase assay. 31 In a basic peroxidase assay, HRP enzyme will be oxidized by H 2 O 2 . This oxidized HRP in turn will remove one electron from TMB, which will form two intermediate oxidation state products.…”

Paper-based microfluidics in sweat detection: from design to application

“…41 The success of wax printing has led to the development of fabrication methods enabling the creation of hemi-and fully enclosed channels within the paper. 42,54 Laser cutting and shaping makes paper thin and easy to fracture, 55 while the flexographic printing lacks reproducibility and flexibility.…”

Peroxidase-like Activity of Aptamer-Gold Nanoparticles for Selective and Sensitive Fluorescence Detection of Low-Density Lipoproteins

“…Nanozymes such as nitrogen-doped carbon dots (N-CDs), Fe 3 O 4 nanomaterials, , vanadium-doped porous Co 3 O 4 nanoparticles, N-CDs/Ni-MnFe-layered double hydroxides (N-CDs/Ni-MnFe-LDHs), Pt/CeO 2 , and prussian blue (PB)-based nanomaterials provide inherent enzyme-like properties, which offer various advantages, including low cost, easy preparation, biocompatibility, and high stability. , …”