الفهرس 
General IntroductionOnly 14 pages are availabe for public view
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Abstract
- The thesis content can be portrayed briefly as four chapters:
• Chapter (I): General Introduction:
- This chapter includes a brief review of the current state of the art in potentiometric solid-contact ion-selective electrodes and solid-contact ion selective electrodes.
• Chapter (II): Screen-printed microsensors using polyoctyl-thiophene (POT) conducting polymer for ultra-trace detection of azides
- This chapter describes the preparation, description and characterization of two novel all-solid-state potentiometric sensors for the detection of azide ion. The sensors are based on the utilization of iron II-phthalocyanine (Fe-PC) neutral carrier complex and nitron-azide ion-pair complex (Nit-N3-) as active detecting selective receptors, tetradodecylammonium tetrakis(4-chlorophenyl) borate (ETH 500) as lipophilic cationic additives and poly(octylthiophene) (POT) as the solid contact material on carbon screen-printed sensor made from a ceramic substrate. Varied pH ranged from 6 to 9 was applied, and the sensors display rapid, linear potentiometric response for low azide concentration and low detection limit for Fe-PC/POT/and Nit-N3-/POT based sensors. The high potential stability and sensitivity of the designed sensors are confirmed by electrochemical impedance spectroscopy (EIS) and constant-current chronopotentiometry measurement methods. Strong membrane adhesion and absence of delamination of the membrane are also verified. The fabricated sensors are successfully applied for azide quantification in synthetic primer mixture samples.
• Chapter (III): Single-walled carbon nanotubes (SWCNTs) as solid-contact for detection of ClO4- in fireworks and propellants analysis
- This chapter displayes trustworthy, robust, stable, and cheap solid-contact ion-selective electrodes (ISEs) for perchlorate detection in fireworks, fertilizers and gun powder. Single-walled carbon nanotubes (SWCNTs) were utilized as solid-contact material and indium (III) 5, 10, 15, 20-(tetraphenyl) porphyrin chloride (InIII-porph) as an ion carrier. The sensor had an enhanced sensitivity towards ClO4- ions. The short-term potential stability and the double-layer capacitance were examined by chronopotentiometric and electrochemical impedance spectroscopy (EIS) measurements, respectively. The sensor is used for ClO4- determination in fireworks and propellant powders. The results fairly agree with data obtained by ion chromatography.
• Chapter (IV): Improved solid-contact nitrate ion selective electrodes based on multiwalled carbon nanotubes (MWCNTs) as an ion-to-electron transducer
- This chapter shows the possible improvement of the functional features, reliability and selectivity of solid-contact nitrate-selective electrodes (SC/NO3--ISE). This is attained by the application of nitron-nitrate (Nit+/NO3-) ion conjugation complex and inserting MWCNTs as an ion-to-electron transducer between the ion sensing membrane (ISM) and the electronic conductor glassy carbon substrate (GC).The potentiometric performance of the fabricated electrode showed a Nernstian slope -55.1 ± 2.1 (r²=0.997) mV/decade in the range from 8.0×10-8 - 10-2 M with a detection limit of 2.8×10-8 (1.7 ng/mL). selectivity, repeatability and reproducibility of the proposed sensors was considerably improved as compared to the coated disc electrode (GC/NO3-ISE) without insertion of MWCNTs layer. Short-term potential stability and capacitance of the proposed sensors were tested using current-reversal chronopotentiometric technique. The potential drift in presence of MWCNTs layer decreased from 167 μVs-1 (i.e. in absence of MWCNTs) to 16.6 μVs-1. In addition, the capacitance enhances from 5.99 μF (in absence of MWCNTs) to 60.3 μF (in the presence of MWCNTs). The presented electrodes were successfully introduced in determining nitrate in real samples with different matrices with a good accuracy.