면역 단백질 감지를 위한 다공성 실리콘 나노바이오센서

Abstract

Porous silicon obtained by chemical or electrochemical dissolution of c-Si has shown a great quantity of applications and extensive works on this material has been reported both in the scientific and technological areas. The visible photoluminescence at room temperature of this material reported in 1990 by Cangam has attracted considerable interest due to the possibility of manufacture an integrated optical device on Si. Porous silicon multilayers, sometimes also called porous silicon superlattices, improve the feasibility of optical components realized from this interesting material : distributed Bragg reflectors(DBR) and Fabry-Perot interferential filters, Rugate filters, microcavities with controlled spontaneous emission properties, waveguides, colour-sensitive photodiodes, and resonant cavity light emitting diodes are some of them. By adjusting the electrochemical etching conditions such as alternating current densities, time, and HF concentration, the morphology and porosity of PSi can be easily controlled.Distributed Bragg reflector (DBR) PSi exhibits unique optical properties. DBR PSi has been typically prepared by an applying a computer generated pseudo-square current waveform to the etch cell which results two distinct indices and exhibits photonic structure of Bragg filters. In this paper we investigate the use of a random distribution in the layer thicknesses in order to realize a broadband optical reflector and to such technological motivations, the study of random dielectric multilayers is of interest in the field of one dimensional light localization.|Asymmetric porous silicon-based optical biosensor was developed to specify the biomolecules. Asymmetric porous silicon was generated by an electrochemical etching of silicon wafer using an asymmetric electrode configuration in aqueous ethanolic HF solution. Asymmetric porous silicon prepared by using anisotropic etching conditions displayed Fabry-Perot fringe patterns whose reflection maxima varied spatially across the porous silicon. The sensor system studied consisted of monolayer porous silicon modified with biotin. When the biotin-derivatized asymmetric porous silicon was exposed to avidin in PBS buffer solution, molecular binding caused an increase of its effective optical thickness. The changes of effective optical thickness at different positions of asymmetric porous silicon were measured to specify the biomolecules.