Etched and non-etched polystyrene nanoballs coated with AuNPs on Indium Tin Oxide (ITO) electrode as H₂O₂ sensor

In electro-analytical applications, metallic nanoparticles (NPs) facilitate roughening of the conductive sensing interface and electrochemical signal amplification as a result of some metal NPs catalytic properties. In this study, natural lithography, termed as nanospheres lithography (NSL), was used to fabricate 5 nm thick AuNPs from thermal evaporation system on an Indium Tin Oxide (ITO) substrate patterned with polystyrene (PS) nanoballs (d=100 nm). The electrode substrate was characterized by field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and cyclic voltammetry (CV) and utilized as a sensor to measure H₂O₂. More prominent features were shown by the etched PS on the fabricated electrode that left AuNPs honeycomb-like pattern than the non-etched one. Higher oxidation peak was demonstrated by the etched electrode than non-etched electrode as recorded with cyclic voltammogram, as well as in H₂O₂ measurement. CV outcomes denoted higher surface area at the substrate with etched PS and resulted in a lower limit of detection (LOD) of H₂O₂ than the non-etched substrates.