Farnoush Faridbod

A simple and efficient method was used for surface modification of core-double shell CdSe/CdS/ZnS quantum dots (QDs) by mercaptoacetic acid (MAA) and imidazole (IM) as capping ligands. The resultant QDs were water dispersible and possesed advantages of low toxicity, high photostability and excellent fluorescence in comparison with CdSe QDs. The studies showed that the fluorescence intensity of the modified QDs was selectively quenched in presence of copper ions respect to other common metal cations. Thus, it was used as a nanosensor for detection of copper ions in aqueous solutions. In the optimal conditions, Cu²⁺ ion could be detected in the concentration range of 2.0 × 10^–9–1.38 × 10^–6 mol L^–1 with a limit of detection 1.0 × 10^–9 mol L^–1 (1 nM). The new designed nanosensor based QDs was then successfully applied for the determination of Cu²⁺ ions in real samples including tap water, ground water, human urine and human blood serum with satisfactory recovery of 97.8–102.6%.

Background: The risk of inadequate nutrition such as trace elements and vitamin deficiencies is considerable in postmenopausal women. The aim of this study was to compare trace elements (Zinc, Copper and Magnesium) concentration in nail, urine and serum among osteoporotic postmenopausal women with control group in Iran.Methods: Forty eight postmenopausal women aged 36–60 years, were recruited, consisting 30 osteoporotic patients and 18 healthy controls. Blood, nail and urine concentration of Zinc (Zn), copper (Cu) and magnesium (Mg) were determined using Inductively Coupled Plasma -Atomic Emission Spectrometry (ICP-AES) method. Their Bone Mineral Density was measured by Dual X-ray Absorption (DEXA) method.Results: The urine level of trace elements had significant difference between osteoporotic groups and controls (p < 0.001). Moreover Mg level significantly differed in serum between two groups (p < 0.04). There was no statistically significant difference in trace minerals in nail beyond groups.Conclusion: Our findings indicate that Urine Zn level could be considerable an appropriate marker for bone absorption, usage of Zn supplements in postmenopausal women may result a beneficial reduction in osteoporotic risk.

In this work, UV-Vis. electronic spectra of 1-pyridinyl-2-methylene-benzene carbohydrazonic acid (L) have been studied. The different bands observed have been assigned to the proper electronic transitions. The solvatochromic behavior of this compound is investigated by studying their electronic spectra in organic solvents with different polarities. The longer wavelength band is assigned to an intermolecular charge transfer (CT) transition. The solvated H-bonding complexes formed between dimethylformamide and L is also investigated. ΔG, and Kf values of this complex have been determined. Effects of temperature increase and concentration changes on the longer spectroscopic wavelength band of 1-pyridinyl-2-methylene-benzenecarbohydrazonic acid were studied too.

The first asymmetric potentiometric UO₂(II) microsensor is introduced. 5,11,17,23-tetra-tertio butyl(25,27),-bis)2-)n-]2-hydroxy-5-dinitridphenilonitrilidine) amino etoxy(26,28)-di hydroxy calix[4]arene (HAECA) was synthesized. It was found that HAECA can be used as an excellent ionophore in construction of UO₂(II) microsensor. The best performance was obtained with a membrane composition containing 20% PVC, 73% dibutyl phthalate, 5% HAECA, and 2% sodium tetraphenyl borate. The proposed microsensor exhibits a Nernstian slope of 28.5 ± 0.3 mV per decade over a wide concentration range of 1.0 ×10⁻¹⁰–1.0 × 10⁻⁴ M and a detection limit of 6.0 × 10⁻¹¹ M. The potentiometric response of the sensor is independent to the pH of the solution in the range of 2.2–3.6.

Application of potentiometric electrodes in drug measurements, offer the advantages of speed and ease of preparation and procedures, relatively fast response, wide linear dynamic range, portability and low cost. The majority of drug sensors are based on ion pair complexes, to overcome the difficulties of synthesizing very differently shaped ionophores, which is an obligation caused by the very wide range of shapes of the drugs. The above-mentioned advantages are the result of the growing trend of development, and use of sensors in drug analysis. Levothyroxine, also L-thyroxine, synthetic T4, or 3,5,3’,5’-tetraiodo-L-thyronine, is a synthetic form of thyroxine (thyroid hormone). Levothyroxine is a replacement for a hormone that is normally produced by your thyroid gland to regulate the body's energy and metabolism. Levothyroxine is given when the thyroid does not produce enough of this hormone on its own. Observation of the patients who are used levothyroxine tablets but still have problem with their thyroid, leads to analysis the pharmaceutical formulation used for the first step. For this purpose, this research work introduces a novel levothyroxine potentiometric sensor for determination of levothyroxine in pharmaceutical formulation. This simple device can be easily used either by the pharmaceutical factories produce levothyroxine tablet in quality control unites or even by the physicians face to such patients. The proposed sensor shows a fast (~30 s), stable and Nernstian response (58.6±0.3 mV/decade) over a relatively wide levothyroxine concentration range of 1×10-5 to 1×10-2 mol L-1. Validation of the method shows suitability of the sensors for applies in the quality control analysis of levothyroxine in pharmaceutical formulation. Nothing to Disclose: FARF, EN-E, BL, PN, MRG

The need for the prompt lutetium determination becomes urgent when considering that the risk of its penetration into humans, animals, and plants results in the alteration of the physiological processes of their cells. Subsequently, it is of great importance to develop an efficient method for the accurate lutetium determination. This study demonstrates the development of a N,N′‐bis(2‐pyridinecarboxamide)‐1,3‐benzene (BPMB)‐Lu(III) potentiometric membrane sensor, illustrating the best overall performance in comparison with the other respective sensors in the literature. In detail, the sensor displayed a lower detection limit of 6.3×10⁻⁷ M, a Nernstian response in the range of 1.0×10⁻⁶ M–1.0×10⁻¹ M and a prompt response time (∼5 sec). Its reproducibility was satisfactory with a relatively good discriminating ability for the lutetium(III) ions among many common cations and lanthanide ions. For the pH values of 3.0–7.5, the sensor potential response remained constant despite the pH fluctuations. This electrode performance was accomplished with a membrane composition of 30% PVC, 63% benzyl acetate (BA), 5% BPMB, and 2% sodium tetraphenylborate (NaTPB). In parallel, the sensor was evaluated by determining the lutetium ion concentration at a Certified Reference Material (CRM), named the Coal and Fuel Ash analysis (FFA 1 Fly Ash), synthetic human serum, and some soil and sediment samples.