Colorimetric Analysis of Glucose Oxidase-Magnetic Cellulose Nanocrystals (CNCs) for Glucose Detection

Abstract

Glucose oxidase (EC 1.1.3.4) sensors that have been developed and widely used for glucose monitoring have generally relied on electrochemical principle. In this study, the potential use of colorimetric method for glucose detection utilizing glucose oxidase-magnetic cellulose nanocrystals (CNCs) is explored. Magnetic cellulose nanocrystals (magnetic CNCs) were fabricated using iron oxide nanoparticles (IONPs) and cellulose nanocrystals (CNCs) via electrostatic self-assembly technique. Glucose oxidase was successfully immobilized on magnetic CNCs using carbodiimide-coupling reaction. About 33% of GOx was successfully attached on magnetic CNCs, and the affinity of GOx-magnetic CNCs to glucose molecules was slightly higher than free enzymes. Furthermore, immobilization does not affect the specificity of GOx-magnetic CNCs towards glucose and can detect glucose from 0.25 mM to 2.5 mM. Apart from that, GOx-magnetic CNCs stored at 4 °C for 4 weeks retained 70% of its initial activity and can be recycled for at least ten consecutive cycles.

Magnetic cellulose: does extending cellulose versatility with magnetic functionality facilitate its use in devices?

“…174 Combining preformed particles and CNCs have been reported to lead to random attachment of the magnetic nanoparticles on the cellulose due to the ionic interaction that is distributed along the cellulose. 175 On the other hand, the mere immersion of biopolymers in an MnFe 2 O 4 nanoparticle dispersion resulted in no observed interaction between the cellulose and its magnetic components. 176 The question of the nature and the strength of the bond between the magnetic particles and cellulose after co-precipitation appears to have been established; however, it continues to be discussed.…”

Enzymes of an alternative pathway of glucose metabolism in obligate methanotrophs

“…The concentration of glucose 1-phosphate (δ 5.46, m, 1H), glucose 6-phosphate (δ 5.37, m, 1H), trehalose (δ 5.20, d, J = 3.8 Hz, 1H, 1′H), maltose derivative/maltotriose (δ 5.41, br 1,1′CH), glucose (δ 5.24, d, J = 3.8 Hz, 1H), sucrose (δ 5.42, d, J = 3.8 Hz, 1H) were measured by using H 1 NMR.The sucrose and glucose contents were additionally measured using anthron reagent 8 and ABTS assay 37 . Analytical and NMR data for sucrose and glucose are practically coincided; Table 3 shows the data obtained by analytical methods.…”

Enzymes of an Alternative Pathway of Glucose Metabolism in Obligate Methanotrophs

“…Additionally, sucrose and glucose concentration was determined using anthron reagent 8 and ABTS assay 32 .…”