Novel approach of SERS sensors AgNPs/PSi by incorporated MWCNT

• Excellent modification of the morphological properties of of PSi layer. • A new simple and efficient deposition of AgNPs/MWCNT/PSi by ion reduction process. • Further increase in surface area by incorporating MWCNTs. • Extra Efficient & sensitive hybrid structures based AgNPs/MWCNTs/PSi. In this study, two types of nano photonics sensors silver nanoparticles/porous silicon (AgNPs/PSi) and silver nanoparticles/multi wall carbon nanotube/porous silicon (AgNPs/MWCNT/PSi) were formed and tested extensively. The porous silicon (PSi) substrate was formed by laser assisted chemical etching process at laser intensity 150 mW/cm 2 and wavelength 630 nm respectively. The formation of these types of nano photonics SERS sensors were carried out by a simple and low cost dipping process of porous silicon (PSi) in silver nitrate (AgNO 3 ) and multi wall carbon nanotube (MWCNT) solution fixed concentration of AgNO 3 about (10 −3 M). These sensors were tested at different concentrations of difenoconazole, 10 −5 , 10 −7 , 10 −9 and 10 −10 M at room temperature. The research results showed an excellent sensing behavior of silver nanoparticles/multi wall carbon nanotube/porous silicon (AgNPs/MWCNT/PSi) comparing with the silver nanoparticles/porous silicon (AgNPs/PSi) nanoparticles sensors. Higher enhancement factor with lower limit of detection with multi wall carbon nanotube (MWCNT) were improved by two orders of magnitude, due to the high value of the sensing area after incorporating multi wall carbon nanotube (MWCNT) to nano photonics sensors.