BRCA1 detection by porous silicon double-layer via reflectometric interference Fourier transform spectroscopy

Abstract

Porous silicon double-layer (PSiDL) was fabricated to reduce noise for biosensing measurements via reflectometric interference Fourier transform spectroscopy (RIFTS). The design of the top layer was performed to trap the bio-analyte molecules by their larger diameter pores. However, by constructing the smaller diameter pores on the bottom layer, attempts were made to prevent these molecules from entering the pores as much as possible. Thus, the top layer acted as the sensing layer, whereas the bottom layer played a reference layer role. The Field emission scanning electron microscopy (FE-SEM) revealed that the top and bottom layers had pores with the highest diameter frequency of about 19 and 7 nm, respectively. Surface modification was performed for both layers and was confirmed by Fourier transform infra-red spectroscopy (FTIR) and RIFTS. Modified PSiDL nanostructure was then used to detect the high penetrance breast cancer susceptibility gene, BRCA1, via RIFTS. Examination of both the peaks' location in fast Fourier transform (FFT) of reflection graphs and amplitude value of these peaks was performed. Both analyses showed that the top layer noise could be reduced by using the bottom layer signal.