fluorescence based nano-bio-optic systems as label-free biosensors ‎

The label-free molecular fluorescence techniques provide high sensitivity and selectivity for ‎biomolecules sensing and being rapid, simple, and being less sensitive to matrix effects. fluorescent ‎nanoprobes act as fluorescence nano-bio-optic systems according to different strategies include ‎quenching (turn-off), enhancement (turn-on), quenching-recovery (turn off-on), turn on-off, turn ‎on-off-on and metal enhanced fluorescence (mef). fluorescence resonance energy transfer ‎‎(fret), photo induced electron transfer (pet) and inner filter effect (ife) are powerful and ‎sensitive approaches in which the excitation energy of a donor fluorophor is transferred to the ‎acceptor molecule.‎surface plasmon resonance (spr) is another label-free, real-time and sensitive method that is ‎widely used in biological and medical sciences. spr is the most commonly used optical method for ‎examining protein-protein and protein-ligand interactions, and nucleotide hybridization. this ‎technique as a fundamental analytical tool for investigating the binding parameters and binding ‎mode.‎four main groups of nanoparticles (nanosystems) are metallic nanoparticles (au and ag), ‎bimetallic or alloy nanoparticles, like iron-platinum (fe-pt) and iron-cobalt (fe-co), metal oxide ‎nanoparticles (monps; zno, tio2, v2o5, cuo and ceo2) and magnetic nanoparticles like iron ‎oxide nanoparticles (fe2o3) are used as a luminescent probe or a quencher or as a potent active ‎surface layer in spr.‎‏ ‏recent studies in our laboratory have shown the high potential of these ‎compounds in the development of biosensors and diagnostic systems.‎we have used fret-based nano-systems to determine biological compounds or drugs, ‎including glucose and morphine, as well as spr technique was used to investigate the interaction of ‎protein-protein, protein-dna or protein-ligand. our future studies focus on expanding the use of ‎the unique potential of these two approaches in the diagnosis and treatment of cancer and other ‎chronic diseases.‎