Part I: Optical Biosensors: Today - Optrode-Based Fiber Optic Biosensors (Bio-Optrode) (I. Biran, X. Yu and D.R. Walt); Evanescent Wave Fiber Optic Biosensors (G.P. Anderson and C. Rowe Taitt); Planar Waveguides for Fluorescence Biosensors (K. Sapsford, C.R. Taitt and F.S. Ligler); Surface Plasmon Resonance Biosensors (J. Homola, S.S. Yee and D. Myszka); Flow Immunosensors (A.W. Kusterbeck and D.A. Blake); Fluorescence Lifetime Biosensing: Entering the Mainstream (R.B. Thompson); Electrochemiluminescence (M.M. Richter); Plasmonic SERS Molecular Sentinels: A New Biosensing Approach (T. Vo-Dinh); Part II: Optical Biosensors: Tomorrow - Cavity Ring-down Biosensing (P.B. Tarsa and K.K. Lehmann); Cantilever Biosensors (M. Alvarez, K. Zinoviev, M. Moreno and L.M. Lechuga); Protein Microarray Technologies – With an Array of Applications (T.O. Joos, J. Bachmann and J.W. Jacobson); Single Domain Antibodies: Rugged Recognition Elements for Tomorrow’s Biosensors (J.L. Liu, G.P. Anderson, A. Hayhurst and E.R. Goldman); Nucleic Acids for Reagentless Biosensors (E. Jeong Cho, J-W. Lee, M. Rajendran and A.D. Ellington); Imprinted Polymers and their Application in Optical Sensors (S.A. Piletsky and A.P.F. Turner); Nanoparticles for Biosensors (H. Kang, M. O’Donohue, L. Wang, Y.C.Y. Cao and W. Tan); Fluorescence-based Intracellular Sensing (I.L. Medintz and J.B. Delehanty); Microfluidics (A.D. Stroock); Index.