Wiring of Glucose Oxidizing Flavin Adenine Dinucleotide-Dependent Enzymes by Methylene Blue-Modified Third Generation Poly(amidoamine) Dendrimers Attached to Spectroscopic Graphite Electrodes

• Published in: Electrochimica acta 2016-04, Vol.197, p.263-272
• Main Authors: Castaing, Victor, Álvarez-Martos, Isabel, Ferapontova, Elena E.
• Format: Article
• Language: English
• Subjects: Dendrimer; Dendrimers; Electrodes; Electron Transfer; Electronics; Enzyme Electrode; Enzymes; Glucose; Graphite; Methylene Blue; Oxidation; Spectroscopy; Wiring
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2016.01.217

[Display omitted] •Methylene blue(MB)-labelled 3G dendrimers electronically wire flavoenzymes to graphite electrodes.•Dendrimer-templated organization of MB improves electron transfer efficiency.•Covalent attachment of dendrimers to graphite provides stability of binding superior to S-Au.•Sugar-oxidizing hexose oxidase can be wired with no loss of FAD and electrocatalytic activity. Electro-enzymatic biotransformation requires an efficient and robust electronic communication between the biomolecules and electrodes, often performed by the relevant electron transfer (ET) mediating systems. Of those, redox-labeled dendrimeric structures, biocompatible and bearing spatially ordered multiple redox centers, represent an advanced alternative to the existing approaches. Here we show that methylene blue (MB)-labeled G3 PAMAM dendrimers covalently attached to the high-surface area spectroscopic graphite (Gr) electrodes form stable and spatially resolved electronic wires, characterized by the heterogeneous ET rate constant of 7.1±0.1s−1; they can be used for electronic wiring of glucose-oxidizing FAD-containing enzymes, such as hexose oxidase (HOX), and further bioelectrocatalysis of glucose oxidation, starting, at pH 7, from -100mV vs. Ag/AgCl. Thus, dendrimer-templated electronic wires, comprising MB molecules conjugated to the periphery of the PAMAM and anchored to the surface of cost-effective Gr electrodes represent an efficient and robust tool for protein wiring to electrodes for their perspective bioelectronic applications in biosensors and biofuel cells.