Modern Analytical Methods for the Assessment of Some Neurotransmitters in Human Body by Using Nano Optical Sensors.

Abstract

Chapter 1 This chapter includes general introduction of spectrofluorimetric techniques and some factor affecting on it, biological activity of Schiff base gold complexes, Some review of literature for the use of gold complexes as an optical sensors and a review for the previous methods used for determination of some active drugs (e.g. Lorazepam, Diazepam) Chapter 2 In this chapter a new, simple and accurate spectrofluorimetric method for the determination of Lorazepam concentration was developed. Lorazepam conc. can remarkably quench the luminescence intensity of Au(III) complex (1.1x10-4 mol L−1 ) at λex = 360 nm in dimethylformamide at pH 9.3 . The fluorescence intensity of these band decreases upon adding different concentration of Lorazepam and these confirming the quenching of the energy of Au(III) complex in both ground and excited states. The effect of different parameters, e.g. pH, solvent and foreign ions that control the fluorescence were critically investigated. The calibration curve for the emission intensity of Au(III) complex with [1/ concentration of Lorazepam] at 422 nm shows a wide linear range of concentrations (3.7 x 10-6 – 4.6 x 10-8 mol L−1)with detection limit of (9.4x10-9mol L−1). This method was used successfully for the determination of Lorazepam in human urine and serum samples and shows good recovery, accuracy and precision compared by other previously published methods. Chapter 3 In this chapter a new, simple and accurate spectrofluorimetric method for the determination of Diazepam concentration is proposed. Diazipam concentration can remarkably enhance the luminescence intensity of Tb-OFL complex doped in sol gel matrix (1.1x10-4 mol L−1 ) at λex = 340 nm in dimethylformamide at pH 8.1 . The fluorescence intensity of these band increases especially at 545 nm upon adding different concentration of diazepam and these confirming the energy transfer from diazepam to Tb-OFL complex in both ground and excited states. The effect of different parameters, e.g. pH, solvent and interference from other substances were critically investigated. The calibration curve for the emission intensity of Tb-OFL complex with [concentration of diazepam] at 545 nm shows a wide linear range of concentrations (1 x 10-6 - 2.7 x 10-8 mol L−1)with detection limit of (1.2 x 10-8mol L−1). This method was used successfully for the determination of diazepam in human urine and serum samples and shows good recovery, accuracy and precision compared by other previously published methods.