Fahimeh Jalali

Urea-assisted water electrolysis in an alkaline environment effectively treats urine-rich wastewater and prevents the release of ammonia gas and nitrate pollution into groundwater and drinking water; these contaminants typically result from the discharge of untreated urea into rivers and lakes. On the other hand, Urea-assisted water electrolysis is an efficient method for electrochemically producing hydrogen from water, while simultaneously cleans urea-polluted water. During this process, urea is oxidized at the anode to produce N? and CO?, while pure hydrogen is produced at the cathode and can be easily collected as a valuable green fuel. Compared to conventional water splitting, this method requires 70% less thermodynamic energy to produce H?. Expanding this technology to industrial applications, such as treatment of wastewater plants and farms, could prevent health problems and costs associated with toxic gas emissions, and contribute to the emerging hydrogen economy. In this thesis, two nickel-based bifunctional catalysts were synthesized, and their feasibility for use in the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) was investigated due to their superior electrocatalytic performance. In Chapter 1, an introduction to Urea-assisted water electrolysis and its importance is provided. In Chapter 2, a cerium-nickel bimetallic metal-organic framework (NiCe-MOF) was synthesized on nickel foam (NF) via a solvothermal method to enhance its conductivity and electrochemical properties. The prepared nanocomposite was characterized using various techniques, including X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and Field emission scanning electron microscope (FESEM). The structure of NiCe-MOF/NF was thereby determined. The electrocatalytic performance of the modified electrode toward UOR in an alkaline solution containing 0.5 M urea was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and other electrochemical methods. Compared to stepwise-modified electrodes, the urea oxidation current on NiCe-MOF/NF was substantially increased and exhibited high stability after 200 potential cycles between 0.0 and +0.8 V. Furthermore, chronopotentiometry (CP) performed at a constant current density of 20 mA cm?² showed a very small potential drop for NiCe-MOF/NF over 20 h, confirming its excellent stability. On the other hand, linear sweep voltammetry (LSV) studies showed excellent electrocatalytic performance towards HER (in KOH, 1 M), with an overpotential of 145 mV at a current density of 10 mA cm?². Furthermore, CP stability tests demonstrated good stability of the proposed catalyst during 20 h of HER operation. The fabricated two-electrode cell, consisting of (-)NiCe-MOF/NF?NiCe-MOF/NF(+), required only 2.22 V to reach a current density of 100 mA cm?² and exhibited excellent stability, with just a slight voltage drop after 20 h of Urea-assisted water electrolysis. The superior electrochemical performance toward urea oxidation and hydrogen evolution was attributed to the effective synergy between nickel and cerium within the MOF structure. In Chapter 3, a chalcogenide was employed in the preparation of an efficient bifunctional electrocatalyst for H2

  Electrochemical water-splitting technology for producing “green hydrogen” has attracted increasing attention to the global mission to replace fossil fuel-based energy sources and reduce CO2 emissions. Briefly, an introduction to water electrolysis and a review of effective catalysts are presented in chapter 1. In Chapter 2, we adopted zeolitic imidazolate frameworks-8 (ZIF-8) as the precursor to fabricate ZnS-MOF via facile sulfidation processes. The ZnS-MOF nanostructures were anchored on the surface of the nickel nanowire (denoted as Ni NW@ZnS-MOF nanohybrids) and their catalytic activity for HER, OER, and overall water splitting were studied. The prepared Ni NW@ZnS-MOF revealed a low overpotentials value of 90 and 260 mV at 10 mA cm?2 for HER and OER in 1.0 M KOH solution, respectively. The alkaline electrolyzer assembled by Ni NW@ZnS-MOF provides a low cell voltage of 1.61 V at 10 mA cm?2 current density to boost the overall water splitting and robust stability for 15 h. The superior electrocatalytic activity of Ni NW@ZnS-MOF is due to the facile and effective electron transfer of Ni NW, accessible active sites of ZnS-MOF, and as well as the synergistic effect of the hybrid structures. This finding provides a synthesis strategy to fabricate an efficient free-noble metal catalyst for energy conversion and storage. Achieving the rational design of nanostructures for efficient oxygen evolution reaction (OER) is crucial for green energy utilization. Chapter 3 synthesized the ZnxFe3-xS4 hollow spheres derived from ZnFe-zeolitic imidazolate frameworks (ZnFe-ZIFs) through solvothermal sulfidation with superior OER activity and stability. The ZnxFe3-xS4 electrocatalyst delivers superior OER activity: it requires only low overpotentials of 235 and 285 mV to achieve current densities of 10 and 50 mA cm?2, respectively, as well as a small Tafel slope of 72 mV dec?1. In an alkaline solution, the hollow ZnxFe3-xS4 nanospheres exhibit exceptional durability in the multi-step chronoamperometry test for 20 h. This work offers a blueprint for the design and synthesis of stateof- the-art sulfide-based OER catalysts.

   Electrochemical sensors are known for their numerous advantages such as simplicity, low cost, high selectivity and high sensitivity. Hence, they have become powerful tools direction measuring various samples including foodstuffs, environment, disease diagnosis, medical surveys and security systems. Electrochemical sensors are >     In the first chapter of this section, a brief introduction of sensor and its types, voltammetric techniques, chemically modified electrode, materials used for electrode correction, check of studied analytes and research history is provided.    In the second chapter, a sensitive and selective voltammetric sensor which based on glassy carbon electrode modified with zirconium oxide-porous carbon/reduced graphene oxide (rGO) nanocomposite for the detection of ascorbic acid (AA) is presented. The platform was obtained by calcination of a metal-organic framework (MOF) attached to graphene oxide. Different methods were used for surface characterization. The electrochemical behavior of prepared electrode for the determination of ascorbic acid was systematically investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Compared with the bare glassy carbon electrode (GCE), ZrO2-PCs/rGO/GCE exhibits much higher electrocatalytic activities toward the oxidation of ascorbic acid (AA) with increasing of peak currents and decreasing of oxidation overpotentials. Under optimum conditions, the modified electrode exhibits linear response to ascorbic acid in the range 1.49×10-1-9.8×10+3?M, with detection limit (S/N = 3) calculated to be 5.2×10-2 ?M. The electrochemical sensor presented the advantages of high selectivity, excellent reproducibility (RSD %= 0.379%) and repeatability (RSD %= 0.162%) and long-term storage stability. In addition to this ZrO2-PCs/rGO/GCE sensor was practically applied for the routine analysis of AA in various food and pharmaceutical samples. In the third chapter, by the method of carbonization of a metal-organic framework (MOF), porous carbon nanocomposite containing zirconium oxide (ZrO2-PCs) was prepared, which was proposed for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The morphology and structure of ZrO2-PCs obtained was characterized by different methods. In addition, the electrode modified with nanocomposite was studied by various electrochemical methods, i.e., cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) to investigate the electrochemical behavior. ZrO2-PCs/GCE showed high selectivity and excellent electrocatalytic activity to discriminate the three biomolecules. At the optimized conditions, wide linear range 1×100-6×10+3, 5×10-1-2.21×10+2, and 5×10-1-2.71×10+2µM of towards AA, DA, and UA in ternary mixture were observed, respectively. The modified electrode offers superior anti-interference capability, good repeatability (RSD %= 2 AA, 2.22 DA, 4.71UA) and reproducibility (RSD %= 2.59 AA, 4.48 DA, 1.37UA) and long-term stability. In addition, ZrO2-PCs/GCE was successfully used for the simultaneous measurement of AA, DA and UA in real samples.

Chapter 1: In this chapter, we briefly review direct methanol fuel cells and the most effective anode catalysts for methanol oxidation. Chapter 2: The lack of low-cost, environmental friendly and efficient electrocatalysts for methanol oxidation in DMFCs has restricted its industrialization; thus, the suggestion of a suitable electrocatalyst can be helpful to solve this problem. Herein microsphere-like the flower of undoped CuS and doped with different percentages of nickel was examined as electrocatalysts for methanol oxidation in alkaline media. The obtained results from different electrochemical measurements including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry showed that the secondary metal doping (in here Nickel), has an egregious effect in electrocatalytic activity improvement. In comparison with undoped CuS and other percentages doped of nickel in CuS (3, 10%), the oxidation current density of methanol was increased on 5% Ni-doped CuS (j~ 140mAcm-2 in 1M methanol); in addition, the electrocatalyst with this percent of nickel (5%) was indicated the lower onset potential than the other electrocatalysts. The good current density and also, the excellent stability (during 6000s) of this electrocatalyst made us to further its investigation toward methanol oxidation reaction (MOR). Chapter 3: A composed structure of MnO2 and (Ni-Cu) sulfide nanospheres as an efficient electrocatalyst for methanol oxidation reaction in alkaline media (0.5M KOH) is suggested here. A simple hydrothermal method was used for the preparation of both (Ni-Cu) sulfide and (Ni-Cu) sulfide/MnO2 electrocatalysts. The final electrocatalyst ((Ni-Cu) sulfide/MnO2) was investigated by different methods, such as X-ray diffraction (XRD), energy-dispersive X-ray spectroscopies (EDX), and field emission scanning electron microscopy (FESEM). The electrocatalytic behavior of (Ni-Cu) sulfide nanospheres and (Ni-Cu) sulfide/MnO2 composite toward MOR was examined by different electrochemical measurements including cyclic voltammetry, electrochemical impedance Spectroscopy, and chronoamperometry. The outcome indicated that the (Ni-Cu) sulfide/MnO2 composite relative to (Ni-Cu) sulfide had lower onset potential toward MOR ,and it showed the higher stability (for 6000s). The MnO2 fabrication on bimetal sulfide of (Ni-Cu) is the responsible for enhancement in the electrocatalytic properties of the proposed composite. It seems that the present work has been able to show the performance of MnO2 as a component of a composite in the manufacture of effective catalysts for methanol oxidation.  

امروزه رسيدن به پاسخ در زمان بسيار كم و در محيط مورد نظر از اهميت الاي برخوردار است. سنسورها اين ويژگي را دارند. كه در زمان بسيار كوتاه و در محيط مورد نظر پاسخ لازم را بدهند. علم شيمي نيز مانند ديگر علوم در سيطره سنسورها قرا گرفته است. اين سنسور ها در شيمي انواع مختلفي دارند كه همه آن ها در يك ويژگي مشترك هستن وآن پيگيري تغيرات ويژگي مورد بررسي است. نوعي خاصي از سنسورهاي شيمي كه تغيرات خواص الكتريكي گونه مورد پيگيري   را دنبال ميكند را سنسورهاي الكتروشيميايي مينامند. سنسورهاي الكتروشيميايي داراي ساختاري ساده براي اندازه گيري گونه هاي مختلف مثل يونها،مولكول ها،آلوادگي هاو داروها   مثل ديكلوفناك و...استفاده مي شوند. انچه اهميت دارد طراحي يك سنسورمناسب براي گونه مورد نظر است .اين كار با كمك نانوذرات مختلف براي افزايش سيگنال الكتريكي و همچنين گزينش پذير كردن سيگنال گونه مورد نظر استفاده مي شود. ما در اين ساختارها از نانوذرات كربني براي افزايش سطح و همچنين افزايش سيگنال الكتريكي استفاده كرديم. از كاربرد ديگر نانوذرات اين است كه مي توانند به عنوان يك اتصال دهنده مانند كوانتوم دات ها استفاده شوند. اگر درساختاار سنسورها از يك جز زيستي استفاده شود به آن ها بايوسنسورگفتتهه مي شود و اگر اين جز يك رشته اي DNAباشد ان را اپتاسنسور((aptasensorگويند.براي اندازه گيري كوكايين و سالمونلا دو اپتاسنسور الكتروشيميايي طراحي شد. اين اپتاسنسور داراي حساسيت بالاو گزينش پذيري در تشخيص كوكايين و سالمونلا بودند. در اين كار از الكترود ITO  استفاد شد براي افزايش سطح و همچنين تثبيت كوالانسي رشته اي DNA  سطح الكترود را باكمك روش تبخير گرمايي توسط طلا اصلاح كرديم. در نيتيجه اين كار و با تغيرات غلطت گونه جريان ثبت شده تغغير مي كند با ايجاد منحني كاليبراسيون پي به غلظت گونه در نمونه هاي مورد بررسي شديم. همچنين گزينش پذيري اپتاسنسور را در حضور گونه هاي مشابه بررسي كرديم و نتايج حاصل نشان دهنده كارايي بالا اپتاسنسور هاي طراحي شده بود.  

   اين پايان نامه حاوي دو پروژه تحقيقاتي مي باشد كه چكيده آن ها در زير آورده شده است:    در بخش اول اين پايان نامه،الكترود كربني شيشه اي با نانولوله هاي كربني چند ديواره ، نانوذرات طلا وپليمر اسيدآمينه سرين   اصلاح شد. مطالعه الكترود اصلاح شده توسط روش ميكروسكوپي الكتروني روبشي FESEM ، EDS ، ولتامتري چرخه اي و طيف سنجي امپدانس الكتروشيميايي وجود يك نانوكامپوزيت رسانا بر روي سطح الكترود را نشان داد. در حضور پروژسترون ، يك پيك اكسيداسيون مشخص به دست آمد كه در پتانسيلهاي كمتري نسبت به الكترود اصلاح نشده ظاهر شد. تركيبات الكترود و شرايط آزمايشگاهي براي تعيين حساس پروژسترون بهينه شدند. يك منحني كاليبراسيون خطي در گستره غلظتي(Mµ0.001-2.0 ياng/ml 0.31 - 636) و حد تشخيص   nM0.2 ( ng/ml0.063) بر اساس( S / N = 3) بدست آمد. تكرارپذيري روش با انجام 6   اندازه گيري تكراري از پروژسترون (1) بر حسب انحراف استاندارد نسبي %RSD   ... محاسبه گرديد. تكثير پذيري روش با تهيه ... الكترد با روش مشابه و اندازه گيري پروژسترون (...مولار) بر حسب %RSD بدست آمد. الكترود اصلاح شده ،در تعيين پروژسترون در نمونه هاي سرم خون انسان و نيز در فرآورده دارويي (آمپول) با موفقيت به كار رفت.       در بخش دوم، يك آپتا حسگر براي اندازه گيري حساس و گزينشي پروژسترون استفاده شد. الكترود كربني شيشه اي با گرافن اكسيد احيا شده ، نانوذرات طلا،پليمر اسيدآمينه آرژنين و آپتامر اصلاح شد. خصوصيات الكترود اصلاح شده توسط FESEM   ،EDS، FTIRطيف سنجي زير قرمز-تبديل فوريه   ولتامتري چرخه اي و طيف سنجي امپدانس الكتروشيميايي بررسي شد ووجود يك نانوكامپوزيت رسانا بر روي سطح الكترود را نشان داد. در حضور پروژسترون ، يك پيك اكسيداسيون مشخص به دست آمد كه در پتانسيل هاي كمتري نسبت به الكترود اصلاح نشده ظاهر شد. تركيب الكترود و شرايط آزمايشگاهي براي تعيين حساس   و گزينشي پروژسترون بهينه شدند. يك منحني كاليبراسيون خطي در طيف گسترده اي (nM     0.083   86.69 ng/mL 0.028–300) و حد تشخيص     M 0.03 ( ng/ml0.009) بر اساس( S / N = 3) بدست آمد. . تكرارپذيري روش با انجام ... اندازه گيري تكراري از پروژسترون (...مولار) بر حسب انحراف استاندارد نسبي %RSD   ... محاسبه گرديد. تكثير پذيري روش با تهيه ... الكترد با روش مشابه و اندازه گيري پروژسترون (...مولار) بر حسب %RSD بدست آمد. الكترود اصلاح شده ،در تعيين پروژسترون در نمونه هاي سرم خون انسان، فرآورده دارويي (آمپول) و نمونه هاي شير باموفقيت به كار رفت.

  In the first work, carbon dots from beef were used for quantitative analysis of ketotifen fumarate. Synthesized carbon dots have a strong fluorescence emission in the range of 416 nm, which were quenched fluorescence in the presence of ketotifen fumarate. The results of the analysis showed that there is a linear relationship in the range of 7 × -5× (M) and the value of 0/3 (µM) was obtained for the detection limit. This method was used to measure ketotifen fumarate in human and urine samples. Relative Standard Deviation (RSD) and Relative Error (Re) for measuring ketotifen fumarate in real samples were acceptable values. In the second work, a simple and cost effective method for spectrofluorimetric determination of cysteine in the presence of silver nanoparticles was proposed by nitrogen doped carbon dots (prepared from isoniazid) based on the carbon dots fluorescence recovery. Variables affecting the reaction such as: PH, carbon volume, silver nanoparticle volume, phosphate buffer concentration and interaction time, were studied. The determination of the cysteine with a dynamic range of 3 × -6 ×   (M) and the detection limit 3 ? 9 ×   molar done. The method was used to determination cysteine in human plasma and urine samples, and relative standard deviations and relative error were reported.In the third work, nitrogen doped carbon dots (prepared from isoniazid) were used for quantitative analysis of melamine in the presence of gold nanoparticles. The absorption spectrum of gold nanoparticles overlapping with the carbon dots emission spectrum causes the fluorescence of the carbon dots to be quenched through the inner filter effect mechanism, then fluorescence of carbon dots recovery by melamine. The amount of carbon dots fluorescence recovery in a range of 1 ×   -1 ×

A fast, sensitive, and simple method using magnetic nanoparticles (M  ) coated by tetraethyl orthosilicate(TEOS) and modified with 1,1-Dimethylbiguanide(Metformin), as an adsorbent has been successfully developed for removal of trace amounts of Pb2+, Cd2+ and Zn2+ from distilled water. In first work, we has been synthesized a new magnetic nanoadsorbent by the covalent immobilization of metformin on the surface of Fe3O4@SiO2 nanoparticles. Size, structure and magnetic property of the prepared magnetic nanoparticles (M  ) were studied by scanning electron microscopy (SEM), XRD, Fourier transform infrared spectroscopy (FT-IR) and Vibrating-sample magnetometer (VSM). The ability of the prepared M   for removing heavy metals ions (Pb2+, Cd2+ and Zn2+) from distilled water was studied. The effects of different affecting parameters on the adsorption characteristics of the modified M   were investigated. Kinetic studies showed that the adsorption of Pb2+, Cd2+ and Zn2+ by metformin functionalized magnetic nanoparticle followed pseudo-second-order model, suggesting a chemisorption process. The adsorption processes fit the Langmuir isotherms well with the maximum adsorption capacities of Pb2+, Cd2+ and Zn2+ onto the modified M   were found to be 5.76, 5.47, and 5.06 mg. g?1, respectively. Excellent adsorption capacity of the modified nanoadsorbent together with other advantages such as reusability, easy separation by an external magnetic field, make it suitable adsorbent for removal of heavy metal ions.   In second work, thiol functionalized magnetic nanoparticles were prepared for the removal of ultra-trace amount of Hg2+ from aqueous samples. The modification of Fe3O4@SiO2 was done by the 3-(Trimethoxysilyl)-1-propantiol to prepare Fe3O4@SiO2–Si-(CH2)3-SH nanoparticles. The morphology of this nanoparticle was characterized by scanning electron microscopy (SEM), and FT-IR. The adsorption of Hg2+ ions was examined by batch equilibrium technique. The effect of initial Hg2+ concentration, pH value, eluent concentration and volume, contact time, and coexisting ions on the efficiency of Hg2+ removal have been investigated. The mercury analysis was performed by continuous-flow cold vapor atomic absorption spectrometry (CV-AAS). Each parameter affecting the extraction and removal processes was carried out. The optimum conditions were found to be 55 mg of sorbent, pH of 6.5, 12 min for adsorption time and 10 mL of HCl (0.1 mol L?1)/thiourea (2% w/v) for the desorption of mercury from loaded M  .

  AbstractThe synthesis of molecular imprinted polymer nanostructures (MIP/  ), based on magnetic core-shells gives access to intelligent nanocarriers for drug delivery with two obvious features of controlled release and targeted delivery by using external magnetic field. This study describes a rational design for the choosing the functional monomer and cross-linker in order to develop a targeted delivery system for Zidovudine (AZT). Two functional monomers methacrylic acid (MAA) and itaconic acid, and two cross-linkers Ethylene glycol dimethacrylate (EGDMA) and Trimethylolpropane triacrylate (TMPTA) were investigated. The imprinting factor for all polymers were calculated according to the adsorption experiment. Regarding the results of polymers imprinting factors, itaconic acid and Ethylene glycol dimethacrylate were chosen. By using core-shell technology, the resulting polymer was synthesized on the surface of magnetic core. Demonstrated, the resultant magnetic polymer had a highest imprinting factor (I = 4.57) compared to other designed polymers (compared to the polymer without magnetic core (I = 2.52)). Afterwards the performance of magnetic-MIP and MIP nanoparticles was tested as anticancer carrier, and the results of various in-vitro experiment were studied. The percentage of cell cytotoxicity for cancer cells increased from 14% for pure drug to 74% for MIP and 91% for magnetic MIP Nano-particle, However, no significant changes was observed in cell cytotoxicity on normal cells.

  Nizatidine is a histamine H2-receptor antagonist. Nizatidine by decreasing the amount of stomach acid production, commonly used in treatment of gastro-esophageal reflux disease(GERD) and peptic ulcer disease (PUD).In this study the nizatidine tautomer’s stability, structural data, HOMO and LUMO orbitals (energies and shapes), ?EHOMO-LUMO gaps, UV data and graphs, dipole moments, Mulliken charges, thermodynamic and kinetic stabilities in aqueous media as a biological solvent and some of the different media (vacuum, Et-OH, DMSO) were investigated for the tautomers of nizatidine by density functional theory (DFT)-B3LYP/631-G** method. The results presented that the probability of the compatibility and adaptability of which tautomer (T1-T3) are better than the other tautomer for adapted interaction with the H2-receptor pattern and structural map.

In this thesis we report the fabrication of copper nanoparticles on the multi-walled carbon nano-tubes (MWCNTs) composite film modified glassy carbon electrode ((Cu  /MWCNTs/GCE)) and it was characterized by cyclic voltammetry, a scanning electron microscope and The energy dispersive X-ray (EDX) analysis. Then it was application in the electrochemical Determination of 4-nitrophenol (4-NP) in real samples. Cyclic voltammograms displayed that (Cu  /MWCNTs/GCE) showed high electrochemical catalytic activity contrasted with the MWCNT/ GCE and Cu   / GCE modified. The (Cu  /MWCNTs/GCE) was observed to be appropriate for the selective determination of 4-NP by square wave voltammetry (SWV). Under the optimized condition the fabricated sensor demonstrated two linear concentration ranges from 0.2 to 12.3 and 12.3 to 298.0 ?M with detection limits of 0.06 ?M (S/N = 3). It was proved that this electrode can be utilized for the measurement of (4-NP) in real samples.

  This work is introduces a new electrochemical sensor based on cadmium carbide nanoparticles CdxCy and multi-wall carbon nanotubes MWCNTs modified carbon paste electrode (CPE) for low   level detection of warfarin .The modified electrode was characterized by different methods such as electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The oxidation peak current of warfarin under the optimum experimental conditions was applied for its monitoring for the first time. The calibration curves were linear for warfarin concentrations from 0.009 to 1.4 µM and 1.4 to 500 ?M with a limit of detection of 1.8nM and limit of quantification of 6.6 nM using   differential pulse voltammetric method (DPV). The modified electrode showed excellent stability and was used for determination of warfarin in tablet and human serum with acceptable results.

This thesis contains two research projects that the abstract of them is given below:In the first part of the thesis, an electrochemical sensor for determination of buprenorphine by voltammetric method was created on glassy carbon electrode using multi-walled carbon nanotubes (MWCNTs–GCE) as an electrode modifier. Electrochemical oxidation of the BPR was proposed using voltammetric studies by cyclic voltammetry (CV), and differential pulse voltammetry (DPV) were carried out in Britton-Robinson buffer solution (pH 3.0). Optimizations of parameters including pH, amount of modifier, accumulation time and potential on the anodic peak current of BPR were accomplished. Under the optimum experimental conditions, the linear response range and the detection limit were calculated as 0.008-5.00 ?M and 1.11 nM respectively. Also the selectivity of the modified MWCNTs–GC electrode was studied in the presence of various interferences and accordingly the modified electrode was successfully employed for the determination of Buprenorphine in spiked blood serum and urine samples.  In the second part, carbon paste electrode modified with multi-walled carbon nanotubes (MWCNTs) and ion pair component of buprenorphine-potassium tetrakis(4-chlorophenyl) borate was used for determination of   Buprenorphine by potentiometric method. The response of this electrode in the concentration range of -   M was linear and a Nernstian slope of 58.1 mV dedecade-1 was obtained. Also the detection limit of 0.04 ?M was calculated. The modified carbon paste electrode had the response time about 6 s and in the pH range from 3 to 9 the potential of the solution is independent from pH. The selectivity of the modified electrode was studied in the presence of various interferences and accordingly was successfully employed for the determination of Buprenorphine in spiked blood serum and urine samples.  

Here, we report a facile and greener synthetic approach Carbon dots by hydrothermal treatment grape and persimmon juice, a bio-resource, in a glass bottle. C-dots can also act as excellent electron acceptors and electron donors, and have promising potential to be oxidized or act as reduce agents. In this paper we will determine the levels of iron present in the tap water,mirage water and river water based on the formation of a coloured complex between iron(II)and 1,10-phenanthroline. Since the iron present in the water predominantly exists as Fe3+, it is necessary to first reduce Fe3+ to Fe2+.This is accomplished by the addition carbon dot.Phenolic compounds are related to healthy dietary habits since they are commonly found in fruits and vegetables.in this work we can determination total phenolic contents of carbon dot by the Prussian blue method and thus determination of carbon dot reducibility. This Results are typically expressed as mg gallic acid/ g sample  

  1. Sensitive determination of nanomolar concentrations of methadone by differential pulse adsorptive stripping voltammetry in biological and pharmaceuticals samples based on electropolymerization of L-arginine on glassy carbon electrode. And 2. Differential pulse adsorptive stripping voltammetric determination of nanomolar concentrations of trimipramine based on electropolymerization of ?- cyclodextrin and L-arginine on glassy carbon electrode.    

In the first work, we presented a simple, sensitive and selectivity method for Spectrophotometric measuring of hydrogen sulfide in the samples of air by Rhodamine B. This method is as a reagent in an acid environment based on Hydrogen Sulfide reaction with Rhodamine B. Rhodamine B had the maximum emission in wavelength of 548 nm and increasing the Hydrogen Sulfide for doing calibration in concentration range of 0.50- 20.00 mg L-1 by determination range of 0.08 mg L-1 is linear. The optimal conditions of variables, that have effect on reaction, were investigated by using from Central Composite Design (CCD) method. The mentioned method was successfully used for measuring Hydrogen Sulfide in air samples including the environmental air of water and wastewater refinery of Faraman Industrial Town and environmental air of Sulfur Springs of Mahidasht. RSD is calculated less than 5% in real samples in measuring Hydrogen Sulfide and this method is without any interventions. For investigating validity of findings resulted from this method, Methylene Blue Standard Method was used for measuring Hydrogen Sulfide   In the second word, one Paper Bale Sensor was proposed as a method for measuring data resulted from colorimetric in place which is a simple and the most low cost solution for measuring Hydrogen Sulfide in the Air. is a 1.2 cm diameter plane paper disk which has been stained to Rhodamine B and HCl reagents with optimal concentrations obtained by response level method. After introducing standard sample/ solution to sensor, the Hydrogen Sulfide with Rhodamine B reagent responded on sensor and created a dull pinkish combination. image was captured 20 minutes after sample increasing and the Hydrogen Sulfide for doing calibration in concentration range of 0.50- 20.00 mg L-1 by determination rangy of 0.08 mg L-1 was linear. The mentioned method was successfully used for measuring Hydrogen Sulfide in air samples including the environmental air of water and wastewater refinery of Faraman Industrial Town and environmental air of Sulfur Springs of Mahidasht

This study was designed to examine the interaction of Thioridazine (TRZ) with calf thymus deoxyribonucleic acid (ct-DNA) under physiological conditions. To understand the action mechanism between TRZ and ct-DNA, the binding of TRZ with ct-DNA was investigated by a combined experimental and computational approach. Viscosity measurements, different spectroscopic methods (UV/Vis spectrophotometry, spectrofluorimetry and circular dichroism) and docking studies were used to study the process. A competitive binding experiment and effect of ionic strength mensuration were carried out to investigate the binding mechanism of TRZ and ct-DNA. The binding constant for the interaction of TRZ with ct-DNA at 298, 310 and 315 K were 3.00, 8.33, 23.33 ×104 mol-1 respectively by using UV/Vis absorption. The thermodynamic parameters were obtained by the UV/Vis absorption method, which suggested that hydrophobic force might play a major role in the binding of TRZ to ct-DNA. Furthermore, the drug induces detectable changes in the CD spectrum of ct-DNA as well as changes in its viscosity.