Departamento de Química e Biotecnologia e Engenharia de Bioprocessos, CAP-UFSJ, Rod. MG 443, Km 07, Ouro Branco, MG 36497-899, Brazil.
Departamento de Física, FFCLRP-USP, Av. Bandeirantes, 3900, Ribeirão Preto, SP 14040-901, Brazil.
Enzyme Microb Technol. 2024 Jun;177:110428. doi: 10.1016/j.enzmictec.2024.110428. Epub 2024 Mar 16.
The sensing modified electrode was prepared using glucose oxidase immobilized onto vanadium pentoxide xerogel with glass/FTO as support electrode to evaluate the possibility to construct a VO/GOx Extended Gate Field Effect Transistor biosensor. Previously, our studies exhibited a sensitivity of VO of 58.1 mV/pH. The use of Nafion® onto VO/GOx caused a decrease of mass loss after several cycles compared to the modified electrode without Nafion® during the EQCM and cyclic voltammetrics studies. Electrical characterization of VO/GOx demonstrated a tendency to stability after 200 s as a function of applied current. In presence of glucose and in different pH, the current decreased when the glucose concentration increased due to the lower active sites of enzyme. After ten voltammetric cycles, the total charge tends to structural stability. In pH = 5.0, the modified electrode based on VO/GOx Extended Gate Field Effect Transistor presented more tendency to sensitivity in different concentration of glucose.
采用戊酸氧钒干凝胶固定葡萄糖氧化酶，以玻璃/FTO 作为支持电极，制备了传感修饰电极，以评估构建 VO/GOx 扩展栅场效应晶体管生物传感器的可能性。此前，我们的研究表明，VO 的灵敏度为 58.1 mV/pH。在 EQCM 和循环伏安法研究中，与未使用 Nafion®的修饰电极相比，Nafion®在 VO/GOx 上的使用导致经过多次循环后质量损失减少。VO/GOx 的电特性分析表明，在施加电流的作用下，200 s 后呈现出稳定的趋势。在存在葡萄糖和不同 pH 值的情况下，由于酶的活性位点减少，电流随着葡萄糖浓度的增加而降低。经过十个伏安循环后，总电荷趋于结构稳定。在 pH = 5.0 时，基于 VO/GOx 扩展栅场效应晶体管的修饰电极在不同浓度的葡萄糖中表现出更高的灵敏度。
