Sol‐Gel Derived Nanostructured Metal Oxide Platform for Bacterial Detection

Abstract

AbstractO1 gene based 24‐mer single stranded deoxyribonucleic acid probe (ssDNA) has been immobilized onto sol‐gel derived nanostructured zirconium oxide (NanoZrO2) film fabricated onto indium‐tin‐oxide (ITO) coated glass plate to detect Vibrio cholerae. The X‐ray diffraction and Atomic Force Microscopy techniques have been used to characterize the nanostructured ZrO2 (particle size of ∼ 30–40 nm) and the ssDNA/ZrO2 bioelectrode. The hybridization of ssDNA/ZrO2 bioelectrode with the complementary and genomic DNA has been investigated using differential pulse voltammetry. The results of electrochemical studies suggest that electro‐active and cationic NanoZrO2 provides an effective surface to bind with the phosphate group of DNA resulting in enhanced electron transport. The ssDNA/NanoZrO2 bioelectrode shows a detection range from 1×10−8 to 10 nM of complementary DNA of V. cholerae within 60 s of hybridization time at 25 °C using methylene blue as an electroactive indicator. This O1 gene based metal oxide (ZrO2) sensor exhibits sensitivity for ssDNA/NanoZrO2/ITO bioelectrode as 0.48 µA/nM cm−2 for complementary DNA and 2.34 µA/nM cm−2 for genomic DNA with regression coefficients (R) of 0.991 and 0.995, respectively. This DNA bioelectrode is stable for about 15 weeks when stored at 4 °C.