Enhancement Of Fluorescence Based On Porous Silicon/Au Nanoparticles Photonic Devices

The porous silicon has many advantages,such as the large surface area, biocompatibility, and easy preparation into photonic devices. Porous silicon one-dimensional photonic crystals have excellent modulation effect of electromagnetic wave, it provides a way to further improve the performance of the sensor, studies of porous silicon one-dimensional photonic crystal has aroused extensive attention of the researchers.Gold nanoparticles have unique physical and chemical properties, the surface plasmon resonance of gold nanoparticles makes it present a bizarre optical and electrical properties, it also play the role of signal enhancement and amplification in the detection. In addition, gold nanoparticles, with large surface area, biological affinity good advantages, can greatly improve the fixed and hybridization of DNA content, significantly improve the sensitivity. So there are a large number of researchers have used gold nanoparticles in biological sensing.In this paper, we mainly use the common advantages of porous silicon and gold nanoparticles, combine porous silicon and gold nanoparticles to detect the fluorescence intensity of fluorescein rhodamine 6G, and achieve the purpose of enhanced fluorescence by the porous silicon, the photonic crystal structure and gold nanoparticles. This thesis mainly studies two parts:1. Using the method of electrochemical etching in the n type silicon wafer(resistivity:1-7 Ω cm) to prepare the single layer macroporous silicon, and gold nanoparticles were prepared by sodium citrate reduction method, then gold nanoparticles with a soaking method into the porous silicon, in the process of soaking, we studied the regularity of fluorescence quenching on Au NPs infiltrated into single layer porous silicon film, and studied the gold nanoparticles deposition on macroporous porous silicon to enhance fluorescent rhodamine 6G, when the soaking time of 6 hours, the porous silicon depositions with gold nanoparticles enhanced R6 G fluorescence maximum.2. The porous silicon Bragg reflectors were prepared by p-type silicon wafer(resistivity: 0.02-0.03 Ωcm), using the method of electrochemical etching, and gold nanoparticles were prepared by sodium citrate reduction method, then gold nanoparticles with a soaking method into porous silicon. Using the porous silicon Bragg reflector infiltrated with gold nanoparticles to detect fluorescent rhodamine 6G, achieved porous silicon, gold nanoparticles and Bragg reflector structure triple strengthened R6 G fluorescence.