Efficient detecting of TNT molecules using palladium nanoparticles/ cross shape pores like structure porous silicon

Abstract

A set of porous silicon PSi samples with different cross-shaped pores like structures are successfully synthesized by using double successive wet anisotropic etching process: KOH wet chemical process and laser-assisted etching (LAE) process. Four different forms of palladium nanoparticles are deposited on PSi substrate to fabricate PdNPs/PSi heterostructures. Surface-enhanced Raman scattering (SERS)-active PdNPs/PSi heterostructures are fabricated and investigated for detecting Trinitrotoluene (TNT) molecules. Dipping plating process of PSi in 0.05 M concentration of PdCl2 solution at room temperature for 15 min is used to assemble spread of surface morphologies PdNPs layer over PSi. The results show that the SERS of heterostructures for TNT molecules expos strong reliance on the density of hot-spot junctions more than the local surface plasmonic of PdNPs. Analytical Enhancement factor (EF) of the Raman signal is varied according to the formed density of hot spots regions.