Sensing Aspects of Hybrid SERS Sensors HO-Si Pillars and SiQDs Integrated with Gold Nanoparticles: A Comparative Study

Abstract

Two types of hybrid SERS sensors, have been synthesized through integrated Au nanoparticles   on horizontal oriented (HO)-Si pillars and Silicon quantum dots (SiQDs) nanostructures substrates    . Aggressive Laser-induced etching process ; at high laser intensity of 450, and 550 mW/cm2 and 405 nm wavelength, was used  to create  the HO-Si pillars and SiQDs substrates  respectively . The hybrid SERS sensors have been synthesized with simple, easy –to- work and very low cost dipping technique of HO-Si pillars and SiQDs based-substrates    in HAuCl4   solution. The growth mechanism of Au nanoparticles   has shown clear depending on the   morphology of the based- substrate. In the case of HO-Si pillars, the creation of Au nanoparticles essentially happened at the surface of Si substrate rather than the surface boundaries of HO-Si pillars, whereas with using SiQDs substrate, the deposition of Au nanoparticles mostly occurred around the SiQDs substrate. The better performance of hybrid SERS sensor of  higher development factor,  with minimum  LOD  and  outstanding reproducibility has been attained for SiQDs sensor rather than that  of  HO-Si pillars sensor of about  (7.46 × 108) , (9*10 -14 M) and (4%), respectively.