تهیه و مشخصه نگاری حسگر های نوری و الکتروشیمیایی برای برخی از فلزات واسطه و سنگین و ترکیبات دارویی

fluorescence chemical sensors for the highly sensitive and selective determination of pb2+ , hg2+, co2+ and fe3+ ions in aqueous solutions are described. the ion sensing system was prepared by incorporating lipophilic ligand (l) as a neutral ion-selective fluoroionophore in the plasticized pvc membrane containing sodium tetraphenylborate or potasium tetrakis (p-chlorophenyl) borate as a liphophilic anionic additive. the preliminary spectrofluorimetric complexation studies in solution revealed that the lipophilic ligands (l) forms a highly stable and selective complexes which results in a strong fluorescence quenching of the ligand. the response of the sensor is based on the strong selective fluorescence quenching of l by metal ions. at optimized ph, the proposed sensor display a calibration curve over a wide concentration range with a relatively fast response time of less than 5 min. in addition to high stability, reversibility and reproducibility, sensors show a unique selectivity towards metal ion with respect to common coexisting cations. the proposed fluorescence optodes were successfully applied to the determination of metal ions in different real samples. a highly sensitive electrochemical method for the simultaneous determination of da and ap using poly(mttp) /au modified electrode was reported. the modified electrode was fabricated by electropolymerization of porphyrin using cyclic voltametry. surface characterization of poly (mttp)/ au modified electrodes were investigated using scanning electron microscope (sem). the poly (mttp) /au modified electrode exhibited remarkably electrocatalytic activity toward da and ap oxidation, improving the response currents and lowering their oxidation overpotentials. two well-defined voltammetric peaks at 0.420 v and 0.650 v were observed, corresponding to the oxidation peak of da and ap respectively. experimental conditions such as supporting electrolyte, ph, and scanning rate, etc., were optimized for the investigated method. da and ap give linear response over the range of 5.0 × 10-6 – 2.9 ×10-4 m (r2 = 0.996) and 2.5 ×10-5 – 5.0× 10-4 m (r2 = 0.994), respectively. the lower detection limits were found to be 3.0 × 10-6 m and 1.5 × 10-5 m for da and ap, respectively. no interference was observed with the other biologically important compounds, such as aa, ua. the investigated method showed good stability, reproducibility (1.3% (da) and 2.0% (ap)) and high recovery in pharmaceutical preparation (1.0% (da) and 0.9% (ap)), and human serum (1.5% (da) and 2.1% (ap)). moreover, excellent sensitivity, high selectivity, low detection limits and anti-fouling properties of the sensor, makes this method very suitable for accurate determinations in pharmaceutical and clinical preparations. the sensor was further utilized to determine da and ap levels in commercial drugs and biological fluids; with satisfactory results.