Sol-Gel Derived Nanostructured Metal Oxide Platform for Bacterial Detection

O1 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 258C 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 mA/nM cm � 2