Synthesis of (E)-2-(1H-tetrazole-5-yl)-3-phenylacrylenenitrile derivatives catalyzed by new ZnO nanoparticles embedded in a thermally stable magnetic periodic mesoporous organosilica under green conditions.

ZnO nanoparticles embedded in a magnetic isocyanurate-based periodic mesoporous organosilica (Fe3O4@PMO-ICS-ZnO) were prepared through a modified environmentally-benign procedure for the first time and properly characterized by appropriate spectroscopic and analytical methods or techniques used for mesoporous materials. The new thermally stable Fe3O4@PMO-ICS-ZnO nanomaterial with proper active sites and surface area as well as uniform particle size was investigated for the synthesis of medicinally important tetrazole derivatives through cascade condensation and concerted 1,3-cycloaddition reactions as a representative of the Click Chemistry concept. The desired 5-substituted-1H-tetrazole derivatives were smoothly prepared in high to quantitative yields and good purity in EtOH under reflux conditions. Low catalyst loading, short reaction time and the use of green solvents such as EtOH and water instead of carcinogenic DMF as well as easy separation and recyclability of the catalyst for at least five consecutive runs without significant loss of its activity are notable advantages of this new protocol compared to other recent introduced procedures.

Novel magnetic propylsulfonic acid-anchored isocyanurate-based periodic mesoporous organosilica (Iron oxide@PMO-ICS-PrSO3H) as a highly efficient and reusable nanoreactor for the sustainable synthesis of imidazopyrimidine derivatives.

In this study, preparation and characterization of a new magnetic propylsulfonic acid-anchored isocyanurate bridging periodic mesoporous organosilica (Iron oxide@PMO-ICS-PrSO3H) is described. The iron oxide@PMO-ICS-PrSO3H nanomaterials were characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy and field emission scanning electron microscopy as well as thermogravimetric analysis, N2 adsorption-desorption isotherms and vibrating sample magnetometer techniques. Indeed, the new obtained materials are the first example of the magnetic thermally stable isocyanurate-based mesoporous organosilica solid acid. Furthermore, the catalytic activity of the Iron oxide@PMO-ICS-PrSO3H nanomaterials, as a novel and highly efficient recoverable nanoreactor, was investigated for the sustainable heteroannulation synthesis of imidazopyrimidine derivatives through the Traube-Schwarz multicomponent reaction of 2-aminobenzoimidazole, C‒H acids and diverse aromatic aldehydes. The advantages of this green protocol are low catalyst loading, high to quantitative yields, short reaction times and the catalyst recyclability for at least four consecutive runs.

A sensitive electrochemical genosensor for highly specific detection of thalassemia gene.

Beta thalassemias (ßth) are the result of mutations in the ß-globin gene. In this report, an electrochemical genosensor was made to detect the sequences anent with the ß-globin gene. This biosensor is based on immobilizing 20-mer single stranded oligonucleotide (probe) on the Au nanoparticles- poly (4-aminothiophenol)/ reduced graphene oxide/glassy carbon electrode (AuNPs-PAT/rGO/ GCE) and hybridizing this oligonucleotide along with its complementary sequence (target). The vastness of the probe and target sequences hybridization was studied through differential pulse voltammetry (DPV) along with electrochemical impedance spectroscopy (EIS) using the [Fe(CN)6]3-/4- (1:1) as a hybridization index. The biosensor indicated great efficiency with significant sensitivity along with favorable selectivity. The DPV and EIS responses with the intended concentrations of the sequence were linear varying from 1.0 pM to 400.0 pM (Ip ν log C) and 0.5-400.0 pM (∆Rct ν log C) with a limit of detection of 0.06 pM and 0.035 pM, at the signal to noise ratio of 3σ. The biosensor of the DNA indicated proper discrimination capability to mismatched two-base, three-base, and non-complementary sequences.

A novel voltammetric sensor for citalopram based on multiwall carbon nanotube/(poly(p-aminobenzene sulfonic acid)/ß-cyclodextrin).

Multi-walled carbon nanotube (MWCNTS) coated with poly p-aminobenzene sulfonic acid/ß-cyclodextrin (p-ABSA/ß-CD) film was used as an effective strategy for modification of the surface of glassy carbon electrode (GCE). Electrochemical study and determination of citalopram (CT) were investigated at the p (p-ABSA)/ß-CD/MWCNT/GC using cyclic and differential pulse anodic stripping voltammetric techniques. The results indicate that the p (p-ABSA)/ß-CD/MWCNT/GC significantly enhanced the oxidation peak current of CT. The modified electrode was characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy(SEM) and cyclic voltammetry (CV).The fabricated electrochemical sensor exhibits a fast and reversible linear response toward CT within the concentration ranges of 90 nM-1 µM, 1-11 µM and 11-100 µM with correlation coefficients greater than 0.99 and detection limit of 44 nM. The resulting functionalized polymer film features interesting electrochemical properties such good recovery, reproducibility and selectivity toward CT. The applicability of the proposed sensor was tested by determination of CT in pharmaceutical combinations and human body fluids.