Available online 16 March 2024, 110428

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construct a V2O5/GOx EGFET biosensor for glucose

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decrease in weight loss from modified electrode with the addition of Nafion®

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structural stability of modified electrode reaches the structural stability after 200 s

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Electrochemical study presented a decrease in the charge and present a tendency to stability, favoring the reuse of the biosensor.

Abstract

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 V2O5/GOx Extended Gate Field Effect Transistor biosensor. Previously, our studies exhibited a sensitivity of V2O5 of 58.1 mV/pH. The use of Nafion® onto V2O5/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 V2O5/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 V2O5/GOx Extended Gate Field Effect Transistor presented more tendency to sensitivity in different concentration of glucose.

Section snippetsINTRODUCTION

Diabetes is a disease from glucose metabolism caused for the lack or low absorption of insulin what is hormone produced by the pancreas. Pancreas has a function to break the glucose molecules resulting in energy after the reaction. Consequently, the energy can be harnessed by all the cells. The disease can cause directly impacts in the quality of life of the individuals. In the last 20 years, for example in USA, the number of individuals with diabetes almost duplicated [1], [2]. Based on

Experimental

The vanadium pentoxide gel (V2O5.nH2O) was prepared, according to synthesis described in the literature [31], via acidification of an aqueous solution of sodium metavanadate 0.1 mol L-1. The NaVO3 solution contains polyvanadates species such as [V4O12], which was percolated in an ion exchange resin column (Dowex-50×8) in the acid form. The solution obtained was aged for 7 days and a viscous dark red solution (the vanadium pentoxide gel) was obtained. Then, the xerogel was obtained by dip-coating

Results and Discussions

It was selected different pH values (5.0, 5.2, 5.5 and 5.8) to examine the sensitivity of the sensor. These values were chosen based on information from the enzyme supplier of Datasheet, Sigma-Aldrich. GOx has a broad range of optimal pH values (5.5–6.5) and was active within the pH range of 4–8, while maximum activity was observed at pH 5.5 [37]. Then, the pHs were varied in PBS buffer in order to verify in which pH is obtained the best experimental activity of the enzyme. The concentrations

CONCLUSION

In the electrochemical characterization, the voltammogram cyclics presented a decrease in the charge value observed and followed by a tendency to stability, favoring the reuse of the biosensor. This decreasing of the total charge may be related to V2O5 restructuring due to the insertion and deinsertion of ions during the cycling process. The EQCM allowed to evaluate the loss of mass of the film along the 50 experimental cycles stipulated for cyclic voltammetry technique. Through the technique

Uncited references

[36], [38], [39]

CRediT authorship contribution statement

Elidia Guerra: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Project administration, Resources, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing. Marcelo Mulato: Conceptualization, Data curation, Funding acquisition, Investigation, Validation, Writing – review & editing. Alessandra Felix: Conceptualization, Investigation, Methodology.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work is a collaboration research project of members of the Rede Mineira de Química (RQ-MG) supported by FAPEMIG (Project: CEX - RED-00010-14), CNPq (443215/2014-6), CAPES, INEO and FAPESP.

References (40)National Diabetes Statistics Report - Estimates of Diabetes and Its Burden in the United States, Centers Dis. Control...International Diabetes Federation, International Diabetes Federation, Int. Diabetes Fed. (2023)....A.T. Felix et al.Preparation of V2O5/GOx onto a Screen-Printed Electrode for Sensing Surface of Glucose

J. Electron. Mater.

(2018)

G.E. Silva, K.V.S. Oliveira, R.F. Bianchi, D.T. Cestarolli, E.M. Guerra, Comparison of V2O5 and WO3 sandwicheds, via...E.M. Guerra et al.Titanium Oxide Nanorods pH Sensors: Comparison between Voltammetry and Extended Gate Field Effect Transistor Measurements

Mater. Sci. Appl.

(2014)

E.J. Guidelli et al.Vanadium and titanium mixed oxide films: Synthesis, characterization and application as ion sensor

J. Electrochem. Soc.

(2012)

E.J. Guidelli et al.Ion sensing properties of vanadium/tungsten mixed oxides

Mater. Chem. Phys.

(2011)

D. Bartolomeo et al.Advanced Field-Effect Sensors

Sensors

(2023)

S.A. Pullano et al.EGFET-based sensors for bioanalytical applications: A review

Sensors (Switzerland)

(2018)

E.M. Guerra et al.Synthesis, characterization and electrochemical behavior of the vanadium pentoxide/cetyl pyridinium chloride hybrid material

J. Solid State Electrochem.

(2010)

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