Small molecule detection by reflective interferometric Fourier transform spectroscopy (RIFTS)

A new method for the compensation of matrix effects in biosensing experiments referred to as reflective interferometric Fourier transform spectroscopy (RIFTS) has been developed recently [1]. It employs a porous silicon sensor comprised of two porous silicon layers stacked one on top of the other. The structure has a complicated reflectivity spectrum that can be resolved by FFT analysis leading to three distinctive peaks which are assigned to the layers in the porous silicon structur. If the double layer is appropriately designed, the bottom layer can act as a reference channel. In this paper the specific sensing of small molecules using RIFTS is demonstrated for the first time. Ac-L-Lys-D-Ala-D-Ala has been immobilized to the sensor surface representing the capture probe and vancomycin was used as target analyte. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim