Research On The Application Of Silver Nanoparticles On Black Silicon In Microfluidic Catalysis And SERS Detection

Since the introduction of the concept of lab-on-a-chip in 1990,the interest in and impact of such device has grown explosively as the advantage of miniaturization,integration,automation and portability,and it has been widely used in the fields of chemistry,physics,biology,materials science,medicine,tissue engineering and treatment.The microfluidic catalysis became hotspot because of its less amount of reactants,environmental friendly,high reaction efficiency.But there are some common problems limit the application of microfluidic chip catalytic reaction,like that the catalyst is difficult to fix and easily to flow with the liquid,and the action area of the catalyst is always small.In this research,silver nanoparticles were prepared on black silicon and then applied to microfluidic catalysis and surface enhanced Raman spectrum(SERS)detection.We had set the light path to etch black silicon by femtosecond laser pulse in SF6 atmosphere,and prepared 18 ?m high cone array.We knew that there were a large number of free electrons on the surface of the black silicon through the mechanism of the interaction between the femtosecond laser pulse and silicon surface.The silver ion was reduced by the black silicon into silver nanoparticle and then we studied its growth parameter.The silver nanoparticles prepared on the black silicon with a robust roughness made it an excellent candidate for SERS detection which can detect the concentration of 10-8 M with the Rhodamine as probe molecule.We applied the hierarchical structure into microfluidic chip.The array distribution and throughout the chip from top to bottom made the black silicon microfluidic chip a natural mixer and agitator,which was benefit for the contact among the reactants and the catalyst.As the silver nanoparticles was in situ reduced and bonded with the black silicon,it was hard to move with the fluid.The above characteristics effectively solved the common problems existed in the microfluidic catalysis.We take the catalytic reaction of p-aminophenol from sodium borohydride and p-nitrophenol as an example.The high efficiency catalysis was characterized by SERS and UV-Vis absorption spectrum.