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In this work, glucose oxidase (GOx) cross‐linking to a single‐wall carbon nanotubes (SWCNTs)‐poly(ethylenimine) (PEI) matrix is investigated using cyclic voltammetry (CV) for its direct electrochemistry and kinetics with presence of glucose. The electrochemistry of the bound flavin cofactor, flavin adenine dinucleotide (FAD) of the GOx, is impeded by glucose and recovered at absence of glucose, whereas a non‐specific sugar (e. g. sucrose) has no such effect. The Faradaic current of the GOx in CV decreases when the concentration of glucose increases, while the calculated electron transfer (ET) rate constant (k0) of the GOx presents a monotonic increment manner up to 144 % at 70 mM glucose concentration vs. absence of glucose in a deaerated electrolyte solution. The k0 and Faradaic current changes demonstrate a strong linear relationship to logarithmic value of glucose concentration up to 20 mM. These results suggest that the entrapped GOx, when exposing to glucose, becomes deactivated in the direct electrochemistry. Further mechanistic analysis suggests the ET reaction of GOx shows a responsive correlation to the non‐ergodicity of those active GOx sites. A control experiment using pure FAD immobilized in the matrix doesn't show responses to glucose addition. [ABSTRACT FROM AUTHOR]

Abstract The stability and magnetic susceptibility of galvinoxyl radicals are believed to underpin the behaviour of ferromagnetic organic layers. However, the magnetic response associated with electron transfer from galvinoxyl radicals remains little understood. Here, new findings on magnetically-enhanced electron transfer (MEET) from immobilized galvinoxyl radicals are reported in an electrochemical study using galvinoxyl–gold electrodes. The electron transfer rate constant increases by about 78% in the presence of an external magnetic field of 1.32 mT compared to the electron transfer rate in the absence of a magnetic field. The MEET of organic radical layers on a solid electrode may also open up new avenues for the development of novel ferromagnetic nanostructures and devices. Graphical abstract Unlabelled Image Highlights • A study of the effect of a magnetic field on the electron transfer rate of a ferromagnetic material. • Cyclic voltammetry measurements were conducted using a gold electrode coated with galvinoxyl radicals. • An extended Marcus model was used to calculate the electron transfer rate constant. • A new phenomenon of magnetically enhanced electron transfer was reported. [ABSTRACT FROM AUTHOR]