Mona Yagoubi - Division of Nanobiotechnoloy,Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
Fereshteh Rahimi - Division of Nanobiotechnoloy,Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
Babak Negahdari - Division of biotechnology, Department of advanced technologies in medicine, Faculty of medical Sciences and Technologies, University of Tehran, Tehran, Iran
Ali Hossein Rezayan - Division of Nanobiotechnoloy,Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran

The rapid detection of bacteria is the most important steps before any treatment processes. Therefore in this work we introduce a porous silicon (PSi) based nanobiosensor for rapid and label free detection of E. coli. The surface of nanobiosensor is modified with the Concanavalin A (ConA), a lectin from Jack bean, as biorecognition element that binds to mannose residues of glycoporoteins or glycolipids of target cells. The evaluation of proposed nanobiosensor operation was performed by Reflectometric interference Fourier transform spectroscopy (RIFTS) and the fast Fourier transform (FFT) spectra obtained. The experiment results showed that upon exposure of nanobiosensor surface to bacteria suspension, a significant decrease in intensity of the FFT spectra was observed and E. coli biosensing was performed effectively.