Highly Sensitive ZnO/Au Nanosquare Arrays Electrode for Glucose Biosensing by Electrochemical and Optical Detection

Vinda Zakiyatuz Zulfa; Nasori Nasori; Ulya Farahdina; Miftakhul Firdhaus; Ihwanul Aziz; Hari Suprihatin; Muslikha Nourma Rhomadhoni; Agus Rubiyanto

doi:10.3390/molecules28020617

Highly Sensitive ZnO/Au Nanosquare Arrays Electrode for Glucose Biosensing by Electrochemical and Optical Detection

Molecules. 2023 Jan 7;28(2):617. doi: 10.3390/molecules28020617.

Authors

Vinda Zakiyatuz Zulfa¹, Nasori Nasori¹, Ulya Farahdina¹, Miftakhul Firdhaus¹, Ihwanul Aziz², Hari Suprihatin², Muslikha Nourma Rhomadhoni³, Agus Rubiyanto¹

Affiliations

¹ Laboratory Medical Physics and Biophysics, Department of Physics, Faculty of Sciences and Data Analytic, Sepuluh Nopember Technology Institute, Surabaya 60111, Indonesia.
² Research Center for Accelerator Technology, Research Organization of Nuclear Energy, National Research and Innovation Agency (BRIN), Yogyakarta 55281, Indonesia.
³ Occupational and Safety Department, Nahdlatul Ulama University of Surabaya, Surabaya 60237, Indonesia.

Abstract

The fabrication of a ZnO/Au nanosquare-array electrode was successfully carried out for the detection of glucose concentration in biomedical applications. The fabrication of the ZnO/Au nanosquare array using an ultra-thin alumina mask (UTAM) based on the imprinted anodic aluminum oxide (AAO) template and the direct current (DC) sputtering method was able to produce a very well-ordered nanosquare arrangement with a side size of 300 nm and a thickness of 100 nm. Tests were done to evaluate the performance of the electrode by means of cyclic voltammetry (CV) which showed that the addition of glucose oxidase (GOx) increased the sensitivity of the electrode up to 1180 ± 116 μA mM^-1cm^-2, compared with its sensitivity prior to the addition of GOx of 188.34 ± 18.70 mA mM^-1 cm^-2. A i_ox/i_red ratio equal to ~1 between the peaks of redox reactions was obtained for high (hyperglycemia), normal, and low (hypoglycemia) levels of glucose. The ZnO/Au nanosquare-array electrode was 7.54% more sensitive than the ZnO/Au thin-film electrode. Furthermore, finite-difference time-domain (FDTD) simulations and theoretical calculations of the energy density of the electric and magnetic fields produced by the ZnO/Au electrode were carried out and compared to the results of CV. From the results of CV, FDTD simulation, and theoretical calculations, it was confirmed that the ZnO/Au nanosquare array possessed a significant optical absorption and that the quantum effect from the nanosquare array resulted in a higher sensitivity than the thin film.

Keywords: biomedics; electrode-sensing; glucose; nanosquare arrays; zinc oxide.

MeSH terms

Biosensing Techniques* / methods
Electrodes
Glucose / chemistry
Glucose Oxidase / chemistry
Oxidation-Reduction
Zinc Oxide* / chemistry

Substances

Glucose
Zinc Oxide
Glucose Oxidase

Grants and funding

The authors gratefully acknowledge financial support from Institut Teknologi Sepuluh Nopember (2153/PKS/ITS/2022) and the funding granted by the HETI Program.