Microfluidic paper-based device for colorimetric determination of glucose based on a metal-organic framework acting as peroxidase mimetic

Abstract

This work presents a microfluidic paper-based analytical device (μPAD) for glucose determination using a supported metal-organic framework (MOF) acting as a peroxidase mimic. The catalytic action of glucose oxidase (GOx) on glucose causes the formation of HO, and the MOF causes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by HO to form a blue-green product with an absorption peak at 650 nm in the detection zone. A digital camera and the iOS feature of a smartphone are used for the quantitation of glucose with the S coordinate of the HSV color space as the analytical parameter. Different factors such as the concentration of TMB, GOx and MOF, pH and buffer, sample volume, reaction time and reagent position in the μPAD were optimized. Under optimal conditions, the value for the S coordinate increases linearly up to 150 μmol·L glucose concentrations, with a 2.5 μmol·L detection limit. The μPAD remains stable for 21 days under conventional storage conditions. Such an enzyme mimetic-based assay to glucose determination using Fe-MIL-101 MOF implemented in a microfluidic paper-based device possesses advantages over enzyme-based assays in terms of costs, durability and stability compared to other existing glucose determination methods. The procedure was applied to the determination of glucose in (spiked) serum and urine. Graphical abstract Schematic representation of microfluidic paper-based analytical device using metal-organic framework as a peroxidase mimic for colorimetric glucose detection with digital camera or smartphone and iOS app readout.

A review on advances in methods for modification of paper supports for use in point-of-care testing

“…Besides the above mentioned paper materials, various types of nanomaterials, such as carbon dots (CD) [110,111], silver nanoparticles (AgNP) [41], AuNPs [38,39,43,112,113] and AuNPs@SiO 2 NPs [25] and other nanomaterials [48,50,55], have also been used as detection probes to generate colorimetric signals on the test strips of LFAs ( Table 2). The nanoparticles on LFAs are modified with different biomolecules (e.g., antibody), which can immobilize on conjugation pad and interact with target and then bind the biomolecules on test line for detection.…”

“…A wax-based technology was applied to modify hydrophobic patterns and hydrophobic barriers on paper using a wax printer [27] and a pen-writing approach [28]. Different nanomaterials, such as quantum dots (QDs) [29][30][31][32][33], gold nanoparticles (AuNPs) [24,[34][35][36][37][38][39][40][41][42][43][44][45][46], AuNFs MBA @Ag [47] Cu-Pd/rGO nanoparticles [48], upconverting fluorescent nanocrystals [49], metal-organic framework [50], fluorescent nanoparticles [51], gold nanocage [52], gold nanorods [53], multi-walled carbon nanotubes and graphene oxide [54] and polymer nanoparticles [55], have also been used as reading signal in paper-based POCT devices. The functional papers prepared by these advanced modification approaches significantly extend the application potential of paper as the substrate of POCT devices.…”

New Single-Layered Paper-Based Microfluidic Devices for the Analysis of Nitrite and Glucose Built via Deposition of Adhesive Tape

“…To check the potential interferences in urine that can affect the analytical signal of the μPADs, we specifically studied the effect of some species common in the samples. NO 3 − , C 2 O 4 2− , SO 4 2− , Br − , HCO 3 − , CH 3 COO − , S 2 O 3 2− , F − , H 2 PO 4 − , CO 3 2− , D(+)fructose, uric acid, urea, NaCl, and CaCl 2 were chosen as the interferents [48,51,61]. Comparing the color intensity between the solutions containing interferents only, and the mixture of nitrite or glucose with other interferents investigated the specificity of the developed μPADs.…”

Biofunctionalization of Glass‐ and Paper‐Based Microfluidic Devices: A Review

“…Paper‐based microfluidics are mostly used in combination with colorimetric and electrochemical readout for detecting biomolecules . These devices are made of low‐cost bioactive papers such as nitrocellulose membranes (e.g., Whatman BA85 Protran) or cellulose‐based papers (e.g., chromatography paper) .…”