self-assembly of silver nanoparticles on functionalized glasses via APTES was used to fabricate SERS substrates. For this purpose, silver nanoparticles were synthesized by the wet chemical method and the size distribution of 35 nm was determined, using dynamic light scattering (DLS). UV-Vis spectroscopy was used to characterize the optical properties of the colloidal nanoparticles and also the prepared substrate. After the selfassembly of nanoparticles, the results indicate a slight red shift in the surface plasmon resonance (SPR) peaks. The SEM images showed a uniform distribution of silver nanoparticles on the surface of the glass. Rhodamine B (RB) dye was used as the analyte for studying substrate performances in SERS. However, no significant signals were observed in the Raman spectra of powder and solutions of the RB molecule due to a fluorescence background but using the prepared substrate and its fluorescence quenching effect, the Raman modes were clearly detected in a 10-5 M solution. By decreasing the concentration of the solution to 10-6 M, the Raman peak intensities were greatly reduced in a way that only some of them were detected.

Organophosphorus (OP) forms an important class of toxic compounds. They inhibit acetyl cholinesterase (AChE, EC 3. 1. 1. 7) that results in respiratory and myocardial malfunctions. Pesticides could be accumulated in vegetables and fruits, so detection of them is very important. The goals of this study are decreasing detection time and detection limit of methyl parathion biosensor. In this research the methyl parathion biosensor based on modified glassy carbon (GC) electrode-immobilized AChE is constructed. β-cyclodexterin (β-CD)/chitosan-multiwall carbon nanotube (CS-MCNT) composite, first by polymer wrapping method and then by layer-by-layer selfassembly technique, was prepared. Then different combination of β-CD, CS-MCNT and graphene was deposited on GC electrode. AChE solution (4 mg ml-1) was deposited on the modified GC electrode and dried in air at room temperature. The electrochemical measurement is based on AChE inhibition by methyl parathion (MPT) in the presence of acetyl choline iodide (ACTI) as substrate with cyclic voltammetry method. The results show that using graphene contributes to considerable increasing in current up to 27 μ A. These measurements were done in phosphate buffer (pH = 7. 5) and at 25 ° C. The optimum pH and temperature were 7. 5 and 55 ° C receptively. Detection limit for MPT was obtained 5nM.

The present study deals with the fabrication of ibuprofen-mesoporous hydroxyapatite (IBU-MHA) particles via the incorporation of ibuprofen (IBU)— as a nonsteroidal antiinflammatory drug— into mesoporous hydroxyapatite nanoparticles (MHANPs) using an impregnation process, as a novel drug delivery device. MHANPs were synthesized by a selfassembly process using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant and 1-dodecanethiol as a pore expander under basic condition. The focus of the present study was to optimize the incorporation of IBU molecules into MHANPs under different loading conditions. The synthesized MHANPs and IBU-MHA particles were confirmed by X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FTIR), brunauer– emmett– teller (BET), transmission electron microscopy (TEM), and thermal analysis (TGA). Drug loading (DL) efficiency of IBU-MHA particles was determined by ultraviolet– visible (UV-Vis) spectroscopy, and indicated that the optimized IBU-MHA particles with high DL (34. 5%) can be obtained at an IBU/ MHANPs ratio of 35/50 (mg/mg), impregnation period of 24 h, and temperature of 40 ° C using ethanol as solvent. In-vitro drug release test was carried out to prove the efficiency of IBU-MHA particles as a sustained drug delivery system. A more sustained and controlled drug release was observed for this particles, indicating that it may be have good potential as drug reservoirs for local drug release.

The active substrates in surface enhanced Raman scattering (SERS) spectroscopy were prepared through selfassembly of nanoparticles on functionalized glasses. Colloidal silver nanoparticles (Ag NPs) were prepared chemically in two different sizes by reduction of AgNO3 using trisodium citrate and sodium borohydride. Gold– silver core– shell nanoparticles were also prepared to compare between the optical behaviors of their silver shell and Ag NPs. Absorption spectra of nanoparticles were measured by ultraviolet– visible (UV– Vis. ) spectroscopy, and their approximate sizes were determined by dynamic light scattering (DLS). The core– shell nanoparticles were approximately the same size as the largest Ag NPs (35 nm) and had the same maximum absorption wavelength. The potential of these substrates for detection applications was investigated with 1 M and 0. 1 mM solutions of Raman-active molecule of crystal violet (CV) dye. The Raman enhancement signal was recorded for 0. 1 mM solution with 532 nm laser wavelength, and the obtained spectra enhancement factor (EF) was calculated. EF values indicated that although the silver and gold– silver core– shell nanoparticles had the same surface plasmon resonance, the substrate with smaller Ag NPs had the highest enhancement factor compared to other substrates, which was 9. 5 103, and the core– shell substrate even had a slightly lower enhancement factor in compare with the large Ag NPs.

Cancer is one of the main causes of mortality in the world which is created by the effect of enviromental physico-chemical mutagen and carcinogen agents. The identification of new cytotoxic drugs with low side effects on immune system has developed as important area in new studies of pharmacology. Thymoquinone (TQ), derived from the medicinal spice Nigella sativa (also calledt black cumin) exhibit anti-inflammatory and anti-cancer activities. In this study we employed nanogel-based nanoparticle approach to improve upon its effectiveness. Myristic acid-chitosan (MA-chitosan) nanogels were prepared by the technique of selfassembly. Thymoquinone was loaded into the nanogels. The surface morphology of the prepared nanoparticles was determined using SEM and TEM. The other objective of this study was to examine the in-vitro cytotoxic activity of cell death of Thymoquinone and nanothymoquinone on human breast adenocarcinoma cell line (MCF7). Cytotoxicity and viability of Thymoquinone and nanothymoquinone were assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and dye exclusion assay. Transmission electron microscopy confirmed the particle diameter was between 150 to 200 nm. Proliferation of MCF7 cells was significantly inhibited by Thymoquinone and nanothymoquinone in a concentration-dependent manner in defined times. There were significant differences in IC50 Thymoquinone and nanothymoquinone. TQ-loaded nanoparticles proved more effective compared to TQ solution. The high drug-targeting potential and efficiency demonstrates the significant role of the anticancer properties of TQ-loaded nanoparticles.

Cancer is one of the main causes of mortality in the world which appears by the effect of enviromental physico-chemical mutagen and carcinogen agents. The identification of new cytotoxic drug with low sid effects on immune system has developed as important area in new studies of immunopharmacology. Curcumin is a natural polyphenol with anti-oxidative, antiinflammatory and anti-cancer properties. Its therapeutic potential is substantially hindered by the rather low water solubility and bioavailability, hence the need for suitable carriers. In this report we employed nanogel-based nanoparticle approach to improve upon its effectiveness. Myristic acid-chitosan (MA-chitosan) nanogels were prepared by the technique of selfassembly. Curcumin was loaded into the nanogels. The surface morphology of the prepared nanoparticles was determined using SEM and TEM. The other objective of this study was to examine the in vitro cytotoxic activity of cell death of curcumin and nanocurcumin on human breast adenocarcinoma cell line (MDA-MB231). Cytotoxicity and viability of curcumin and nanocurcumin were assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and dye exclusion assay. Transmission electron microscopy confirmed the particle diameter was between 150 to 200 nm. Proliferation of MDA-MB231 cells was significantly inhibited by curcumin and nanocurcumin in a concentration-dependent manner in defined times. There were significant differences in IC50 curcumin and nanocurcumin. curcumin-loaded nanoparticles proved more effective compared to TQ solution. The high drug-targeting potential and efficiency demonstrates the significant role of the anticancer properties of curcumin-loaded nanoparticles.