Direct Modification of a Glassy Carbon Electrode with Toluidine Blue Diazonium Salt: Application to NADH Determination and Biosensing of Ethanol

Abstract

We describe here the covalent modification of a glassy carbon electrode with toluidine blue (TB) diazonium salt, which is generated in situ from the reaction between the aromatic amino phenyl group of TB and sodium nitrite. TB is attached directly to the electrode surface without any cross‐linking agent or complex matrices. The resulting TB films exhibit excellent electrocatalytic behavior toward NADH oxidation. Low potential detection of NADH is performed at 0.15 V vs. Ag/AgCl. Furthermore, an ethanol biosensor is developed using the TB modified electrode and alcohol dehydrogenase. The great stability and reusability, excellent electrochemical reversibility, technically simple preparation and short preparation time make this method suitable for low‐cost bioelectronical devices.

Scaffold electrodes based on thioctic acid-capped gold nanoparticles coordinated Alcohol Dehydrogenase and Azure A films for high performance biosensor

“…It was found to be 0.63 mM. This value is lower or similar to that reported for other ADH-dyes modified electrodes [46]. This result indicates that ADH retains its great affinity to ethanol after being coordinated to the TO-AuNPs immobilized on AA films.…”

Bioelectrooxidation of Ethanol Using NAD-Dependent Alcohol Dehydrogenase on Oxidized Flexible Carbon Fiber Arrays

“…The apparent Michaelis-Menten constant (K M app ), which gives an indication of the enzyme-substrate kinetics, can be obtained using equation 2, the electrochemical version of the Lineweaver-Burk equation. 50,51 (2) where I SS is the steady-state current after the addition of substrate, I max is the maximum current measured under saturated substrate conditions, and c is the bulk concentration of substrate. K M app was found to be 0.26 mmol L -1 for FCFO-ADH and 28.9 mmol L -1 for FCF-ADH.…”

Fibras de carbono modificadas com a álcool desidrogenase para o estudo da bioeletroxidação do etanol utilizando espectrometria de massas diferencial eletroquímica (DEMS)

“…Em bioeletroquímica, este modelo pode ser adaptado para correntes obtidas de cronoamperometria no estado estacionário [89][90][91] , assim a corrente faradaica pode ser utilizada na obtenção de parâmetros cinéticos pela seguinte equação: Portanto, para verificar se houve alteração na microestrutura das FFC após o tratamento foi realizada análise pela técnica de difração de raios-X (DRX), a qual permite determinação do espaçamento entre os planos grafíticos e o tamanho dos cristalitos. Uma estrutura de grafite monocristalino pertence ao grupo simetria D4 6h , sendo sua cela unitária composta por quatro átomos, na qual a distância entre dois destes átomos é de 1,42 Å e o espaçamento entre as camadas é de 3,345 Å (figura 18a).…”