Iron-Catalysed Remote C(sp3)-H Azidation of O-Acyl Oximes and N -Acyloxy Imidates

The azido group occupies an important position in modern organic chemistry, broadly used as amine surrogates and as anchors in bioconjugation. Despite their importance, examples of selective direct azidation of inert C(sp3)–H bonds remain limited and often require strong oxidative conditions. Herein, we highlight the use of O-acyl oximes and N-acyloxy imidates as directing groups for the selective iron-catalysed azidation of C(sp3)–H bond with trimethylsilyl azide, giving access to various γ-azido ketones and β-azido alcohols in moderate to excellent yields. The iron catalyst is assumed to play a dual role in these catalytic processes: as a reductant to generate the reactive iminyl and imidate radicals, respectively, and as a redox centre to mediate the azido transfer to the translocated carbon radical.

Graphene quantum dot electrochemiluminescence increase by bio-generated H 2 O 2 and its application in direct biosensing

In this study, a novel signal-increase electrochemiluminescence (ECL) biosensor has been developed for the detection of glucose based on graphene quantum dot/glucose oxidase (GQD/GO x ) on Ti foil. The proposed GQD with excellent ECL ability is synthesized through a green one-step strategy by the electrochemical reduction of graphene oxide quantum dot. Upon the addition of glucose, GO x can catalytically oxidize glucose and the direct electron transfer between the redox centre of GO x and the modified electrode also has been realized, which results in the bio-generated H 2 O 2 for ECL signal increase in GQD and realizes the direct ECL detection of glucose. The signal-increase ECL biosensor enables glucose detection with high sensitivity reaching 5 × 10 −6 mol l −1 in a wide linear range from 5 × 10 −6 to 1.5 × 10 −3 mol l −1 . Additionally, the fabrication process of such GQD-based ECL biosensor is also suitable to other biologically produced H 2 O 2 system, suggesting the possible applications in the sensitive detection of other biologically important targets (e.g. small molecules, protein, DNA and so on).

Novel ferrocene-anchored ZnO nanoparticle/carbon nanotube assembly for glucose oxidase wiring: application to a glucose/air fuel cell

Glucose oxidase is immobilized on a ZnO-Fc nanoparticle modified electrode. The new architecture of ZnO supported electron mediators to shuttle electrons from the redox centre of the enzyme to the surface of the working electrode can bring about successful glucose oxidation.

Iron complexes of tris(4-nitrophenyl)corrole, with emphasis on the (nitrosyl)iron complex

The iron complexes of 5,10,15-tris(4-nitrophenyl)corrole have been prepared and characterized by various spectroscopic techniques. The (nitrosyl)iron complex is diamagnetic and its X-ray structure reveals an almost perfectly linear Fe–N–O bond. EPR spectroscopy in conjunction with 15N labelling were used to deduce the redox centre of the one-electron reduction and oxidation products of the (nitrosyl)iron corrole.