SELECTIVE BIOFUNCTIONALIZATION OF POROUS SI NANOSTRUCTURES: TOWARDS DUAL-MODE OPTICAL BIOSENSORS

Analysis of targets, containing two or more interacting analytes, is a major challenge in bio-analytical devices. The capability to detect two analytes in a complex system using a single measurement is necessary in order to monitor and quantify chemical or biological interactions in real-time. Thus, our research aims to develop a dual-mode biosensing platform for simultaneous multi-parameter detection of complex targets. We have designed and fabricated a novel platform based on nanostructured porous silicon (PSi), which is used both as a size and shape-exclusion membrane and as the optical transducer element. The pore size and surface chemistry of the Si nanostructure are tailored to exhibit different chemical functionalities on the top surface and within the internal surface area of the pores, to enable conjugation of different recognition elements. Surface functionalization is confirmed by fluorescent labeling, Refractive Interferometric Fourier Transform Spectroscopy (RITS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and contact angle measurements.