Au-nanoarray by nanosphere lithography sensors for Staphylococcus aureus 16S rRNA

Nanopatterning of Au-nanoarray on an indium tin oxide (ITO) electrode using efficient and low-cost nanospheres lithography (NSL) is reported. Convective self-assembly of 500 nm polystyrene (PS) nanobeads was found to effectively provide a well-ordered monolayer template for Au deposition with the coverage of about 90% on ITO. A simple Au-nanoparticles (AuNPs) spin coating was performed. It is observed that AuNPs immobilized by spin-coating techniques tends to follow the contour of the spherical nanobeads instead of filling the gaps within them, therefore, a distinguished hexagonal ring of Au-nanoarray was generated after nanobeads etching. As used for electrochemical sensor of Staphyloccocus aureus 16S rRNA hybridization detection, this substrate resulted high effective surface area which subsequently gave an excellent limitation of detection (LOD) of 10 pM target DNA. Overall, we have demonstrated an integration of NSL and AuNPs spin-coating for a uniform and high troughput substrate fabrication for electrochemical biosensor development.