Highly efficient silver particle layers on glass substrate synthesized by the sonochemical method for surface enhanced Raman spectroscopy purposes

A fast method for preparing of silver particle layers on glass substrates with high application potential for using in surface enhanced Raman spectroscopy (SERS) is introduced. Silver particle layers deposited on glass cover slips were generated in one-step process by reduction of silver nitrate using several reducing agents (ethylene glycol, glycerol, maltose, lactose and glucose) under ultrasonic irradiation. This technique allows the formation of homogeneous layers of silver particles with sizes from 80nm up to several hundred nanometers depending on the nature of the used reducing agent. Additionally, the presented method is not susceptible to impurities on the substrate surface and it does not need any additives to capture or stabilize the silver particles on the glass surface. The characteristics of prepared silver layers on glass substrate by the above mentioned sonochemical approach was compared with chemically prepared ones. The prepared layers were tested as substrates for SERS using adenine as a model analyte. The factor of Raman signal enhancement reached up to 5·10(5). On the contrary, the chemically prepared silver layers does not exhibit almost any pronounced Raman signal enhancement. Presented sonochemical approach for preparation of silver particle layers is fast, simple, robust, and is better suited for reproducible fabrication functional SERS substrates than chemical one.

Ultrasound-assisted fabrication of a new nano-rods 3D copper(II)-organic coordination supramolecular compound

High-energy ultrasound irradiation has been used for the synthesis of a new copper(II) coordination supramolecular compound, [Cu2(μ-O2CCH3)2(μ-OOCCH3)(phen)2](BF4) (1), ("phen" is 1,10-phenanthroline) with nano-rods morphology. The new nano-structure was characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), FT-IR spectroscopy and elemental analyses. Compound 1 was structurally characterized by single crystal X-ray diffraction. The utilization of high intensity ultrasound has found as a facile, environmentally friendly, and versatile synthetic tool for the supramolecular coordination compounds.

Efficient sonochemical degradation of perfluorooctanoic acid using periodate

A rapid and efficient treatment method, using periodate (PI) for sonochemical oxidation of persistent and bioaccumulative perfluorooctanoic acid (PFOA) was developed. With an addition of 45 mM PI, 96.5% of PFOA was decomposed with a defluorination efficiency of 95.7% after 120 min of ultrasound (US). The removals of PFOA were augmented with an increase in PI doses. In all the PI+US experimental runs, decomposition efficiencies were essentially similar to those of defluorination, indicating that PFOA was decomposed and mineralized into fluoride ions. Lower solution pHs resulted in an increase in decomposition and defluorination efficiencies of PFOA due to acid-catalyzation. Dissolved oxygen increased the amount of IO4 radicals produced, which consumed the more effective IO3 radicals. Consequently, presence of oxygen inhibited the destruction of PFOA. The PFOA degradation rates with different gases sparging are in the following order: nitrogen>air>oxygen. Effects of anions follow the Hofmeister effects on PFOA degradation (i.e., Br(-)>none ⩾ Cl(-)>SO4(2)(-)). Br(-) could react with OH to yield radical anion Br2(-) that enhances the PFOA degradation. A reaction pathway was also proposed to describe the PI oxidation of PFOA under US irradiation.

Sonochemically synthesized biocompatible zirconium phosphate nanoparticles for pH sensitive drug delivery application

The present work reports the synthesis of biocompatible zirconium phosphate (ZP) nanoparticles as nanocarrier for drug delivery application. The ZP nanoparticles were synthesized via a simple sonochemical method in the presence of cetyltrimethylammonium bromide and their efficacy for the delivery of drugs has been tested through various in-vitro experiments. The particle size and BET surface area of the nanoparticles were found to be ~48 nm and 206.51 m(2)/g respectively. The conventional MTT assay and cellular localization studies of the particles, performed on MDA-MB-231 cell lines, demonstrate their excellent biocompatibility and cellular internalization behavior. The loading of curcumin, an antitumor drug, onto the ZP nanoparticles shows the rapid drug uptake ability of the particles, while the drug release study, performed at two different pH values (at 7.4 and 5) depicts pH sensitive release-profile. The MTT assay and cellular localization studies revealed higher cellular inhibition and better bioavailability of the nanoformulated curcumin compared to free curcumin.

Sonochemical synthesis of a nano-structured zinc(II) amidic pillar metal-organic framework

A facile and environmentally friendly nano-scale synthesis of a Zn(II) metal-organic framework (MOF), {[Zn4(BDC)4(bpta)4]·5DMF·3H2O}n (1) (bpta=N,N'-bis(4-pyridinyl)-1,4-benzenedicarboxamide, BDC=1,4-dicarboxylate, DMF=N,N-dimethylformamide), with nanorods morphology under ultrasonic irradiation at ambient temperature and atmospheric pressure has been explored. This MOF has been characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and IR spectroscopy. Some parameters such as concentration of initial reagents, power ultrasound irradiation and time effects on size and morphology of nano-structured compound 1 have been studied.

Sonochemical synthesis of two new copper(II) complexes with azo ligands derived from anthranilic acid and β-naphtol

Nanostructures of two new copper(II) complexes, (CuL1), 0.5EtOH. 1.5H2O (1), [H2L1=5-(4-Carboxy phenyl azo) anthranilic acid], (Cu(L2)2) (2), [HL2=1-(4-Carboxy phenyl azo) 2-naphtol] have been synthesized by the reaction of H2L1 and HL2 with Cu(OAc)2 · H2O through sonochemical process. Calcination of the nano-sized compounds 1-2 yield CuO nanoparticles at 550-450°C under air atmosphere. Metallic copper nanoparticles were prepared by direct calcination of compound 2 in surfactant at 180°C. These nanostructures were characterized by X-ray powder diffraction (XRD) and Scanning Electron Microscopy (SEM). Thermal stability of compounds 1-2 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA).

Highly efficient syntheses of nano mixed-anions lead(II) thiocyanate/nitrate and lead(II) thiocyanate coordination polymers by sonochemical process

Nanostructures of the three-dimensional coordination polymers with the ligand 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (4-bpdh), [Pb(4-bpdh)(NO3)(μ-NCS)]n (1) and [Pb(4-bpdh)(μ-NCS)2]n (2), have been synthesized by a sonochemical process at different concentrations and characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. The solid state structural transformations of nano-compounds 1, 2 by anion-replacement processes under mechanochemical reaction, have been verified by IR and PXRD measurements. The SEM images showed that morphology change occurs on nanostructures during solid state anion-replacements.

Synthesis of folic acid functionalized redox-responsive magnetic proteinous microcapsules for targeted drug delivery

Folic acid (FA) functionalized magnetic bovine serum albumin (BSA) microcapsules (FA-MBMCs) were prepared by a facile sonochemical method, in which FA molecule was immobilized onto the outer walls of microcapsules as a targeting ligand and oleic acid (OA) modifying Fe3O4 magnetic nanoparticles (OA-Fe3O4 MNPs) were wrapped into the microcapsules. The obtained FA-MBMCs possessed a nice spherical morphology with the mean size of 1.4 μm. FA-MBMCs also showed an excellent magnetic and molecular dual-targeted property. Besides, the reductant-triggered diffusion of coumarin 6 suggested superior drug controlled release of FA-MBMCs.

Ultrasound-assisted synthesis of nano-structured 3D zinc(II) metal-organic polymer: precursor for the fabrication of ZnO nano-structure

Nanorods of a three-dimensional Zn(II) metal-organic framework, [Zn₂(btec)(DMF)₂]n (1) (btec=1,2,4,5-benzenetetracarboxylate, DMF=N,N-dimethylformamide), have been synthesized by a sonochemical process and characterized by field emission scanning electron microscopy (FE-SEM), powder XRD and FT-IR spectroscopy. Structural determination of compound 1 was determined by single crystal X-ray diffraction. The thermal stability of compound 1 has been studied by thermal gravimetric analysis (TGA), too. The role of initial reagent concentrations and power ultrasound irradiation and also time, on size and morphology of nano-structured compound 1 have been studied. ZnO nano-structures also were simply synthesized by direct calcination of the single crystals and nano-sized compound 1 at 600 °C. The size and morphology of the ZnO nano-structures are dependent upon the particles size of compound 1. A decrease in the particles size of compound 1 leads to a decrease in the particles size of the ZnO.

Enhanced sonochemical degradation of perfluorooctanoic acid by sulfate ions

This study investigated the effects of sulfate ions on the decomposition of perfluorooctanoic acid (PFOA) by ultrasonic (US) irradiation at various pHs, sulfate doses, powers and temperatures. The removal of PFOA was augmented with an increased sulfate ion concentration, with PFOA being almost completely decomposed in 90min at 25°C with a sulfate dose of 117mM. The two major mechanisms in the sulfate-assisted sonochemical system are the direct destruction of PFOA by cavitation and the indirect destruction of PFOA by sulfate free radicals. The decomposition of PFOA followed pseudo-first-order kinetics and was not influenced by pH. The reaction rate constants decreased with increases in temperature due to decreases in the surface tension of the solution.

Enhancing decomposition rate of perfluorooctanoic acid by carbonate radical assisted sonochemical treatment

Perfluorooctanoic acid (PFOA) is a recalcitrant organic pollutant in wastewater because of its wide range of applications. Technologies for PFOA treatment have recently been developed. In this study, PFOA decomposition by sonochemical treatment was investigated to determine the effects of NaHCO3 concentrations, N2 saturation, and pH on decomposition rates and defluorination efficiencies. The results showed that PFOA decomposition by ultrasound treatment only (150 W, 40 kHz), with or without saturated N2, was <25% after 4 h reaction. The extent and rate of PFOA decomposition and defluorination efficiencies of PFOA, however, greatly increased with the addition of carbonate radical reagents. PFOA was completely decomposed after 4h of sonochemical treatment with a carbonate radical oxidant and saturated N2. Without saturated N2, PFOA was also decomposed to a high (98.81%) degree. The highest PFOA decomposition and defluorination efficiencies occurred in N2 saturated solution containing an initial NaHCO3 concentration of 30 mM. Sonodecomposition of PFOA with CO3(-) radical was most favorable in a slightly alkaline environment (pH=8.65). There isn't any shorter-chain perfluorinated carboxylic acids detected except fluorine ions in final reaction solution.

Solid state and sonochemical syntheses of nano lead(II) chloride and bromide coordination polymers from its nitrate analog via mechanochemical crystal to crystal transformations

Reversible crystal-to-crystal transformations of 3D lead(II) coordination polymers with the ligand 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (4-bpdh), from nitrate analoge [Pb(4-bpdh)(NO3)2(H2O)]n (1) to [Pb(4-bpdh)(NO3)(Br)]n (2), [Pb(4-bpdh)(Br)2]n (3), [Pb(4-bpdh)(NO3)(Cl)]n (4) and [Pb(4-bpdh)(Cl)2]n (5) by solid state anion-replacement processes under mechanochemical reactions, have been studied. The reversible solid state structural transformations of compounds 1-5, by anion-replacement processes under mechanochemical reaction, have been verified by PXRD measurements. Nanoparticles of compounds were synthesized by sonochemical process and characterized by scanning electron microscopy (SEM), powder X-ray diffraction, IR spectroscopy and elemental analyses. The SEM images showed that morphology change occurs during solid state anion-replacements of nanocrystals.

CuO nanosheets-enhanced flow-injection chemiluminescence system for determination of vancomycin in water, pharmaceutical and human serum

A novel, rapid and sensitive CuO nanosheets (NSs) amplified flow-injection chemiluminescence (CL) system, luminol-H2O2-CuO nanosheets, was developed for determination of the vancomycin hydrochloride for the first time. It was found that vancomycin could efficiently inhibit the CL intensity of luminol-H2O2-CuO nanosheets system in alkaline medium. Under the optimum conditions, the inhibited CL intensity was linearly proportional to the concentration of vancomycin over the ranges of 0.5-18.0 and 18.0-40.0 mg L(-1), with a detection limit (3σ) of 0.1 mg L(-1). The precision was calculated by analyzing samples containing 5.0 mg L(-1) vancomycin (n=11) and the relative standard deviation (RSD) was 2.8%. Also, a high injection throughput of 120 sample h(-1) was obtained. The CuO nanosheets were synthesized by a sonochemical method. Also, X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were employed to characterize the CuO nanosheets. The method was successfully employed to determine vancomycin hydrochloride in environmental water samples, pharmaceutical formulation and spiked human serum.

Sonochemical fabrication of mesoporous TiO2 inside diatom frustules for photocatalyst

Mesoporous titanium dioxide (TiO2) has been assembled inside the macropores of diatom frustules by sonochemical condensation of titania precursor, and then thermal treated at an elevated temperature. The resulting hierarchical macro/mesoporous-structures of the TiO2 inside diatom were confirmed by characterizations of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The amount of TiO2 inside the periodic macropores of diatom was controlled by varying the sonication time. It was found that the resultant composite with only 30 wt% TiO2 loading delivered a high photocatalytic performance, even better than that of pure P25. This is attributed to its hierarchical macro/mesoporous structure as it provides a large number of accessible active sites for efficient transportations of guest species to framework binding sites. Other macro/mesoporous structures with a nearly endless variety of functional chemistries and shapes are expected to be produced, leading to a range of novel applications in remediation, molecular transportation and environmental field by using this facile strategy.

Sonochemical syntheses of a new fibrous-like nano-scale manganese(II) coordination supramolecular compound; precursor for the fabrication of octahedral-like Mn3O4 nano-structure

Nanoparticles of a new three-dimensional Mn(II) coordination supramolecular compound, [Mn(L)2(H2O)2] (1), (L(-)=1H-1,2,4-triazole-3-carboxylate), have been synthesized by a sonochemical process and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), FT-IR spectroscopy and elemental analyses. Structural determination of compound 1 reveals the Mn(II) ion is six coordinated, bonded to two nitrogen atoms, two oxygen atoms from the L(-) ligand and two water molecules. The thermal stability of compound 1 both its bulk and nano-size has been studied by thermal gravimetric (TG) and differential thermal analyses (DTA) and compared each other. Concentration of initial reagents effects on size and morphology of nano-structured compound 1, have been studied and shows that low concentrations of initial reagents decreased particles size and also leaded to fibrous-like nanostructures morphology. Mn3O4 nano-structure with an octahedral-like morphology were simply synthesized by solid-state transformation of compound 1 at 650 °C.

Sonochemical degradation of the persistent pharmaceutical carbamazepine

The objective of this work was to evaluate the potential of a sonochemical oxidation process for the degradation of carbamazepine (CBZ). Several factors, such as electrical power, treatment time, pH and initial concentration of CBZ were investigated. Using a 2(4) factorial matrix, the best performance for CBZ degradation (90.1% of removal) was obtained with an electrical power of 40 W, a treatment time of 120 min and an initial pH of 10.0 imposed in the presence of 6.0 mg L(-1) of CBZ. The treatment time and the calorimetric power were the most influential parameters on the degradation rate of CBZ. Subsequently, the optimal experimental parameters for CBZ degradation were investigated using central composite design. The sonochemical oxidation process, applied under optimal operating conditions (at an electrical power of 43 W for 116 min), oxidized 86 and 90% of the initial CBZ concentration of 5.62 mg L(-1) and 8.05 μg L(-1), respectively. During the sonochemical process, CBZ was primarily transformed into anthranilic acid and acridine.