A sensitive dip test strip for detection of formalin (HCHO) in tofu samples based on immobilized pararosaniline (PR) has been developed. The test strip has been fabricated by immobilizing PR reagent on filter paper. By using image color analysis (ImageJ) as the average of ?RGB value as color sensor response, the analytical parameters are obtained from an area of the sensing zone of the test strip using digital output of the color scanner. By using this scanometric method, it is possible to determine HCHO as low as 0.05 mg/L with the concentration range of 2-80 mg/L and the response time of 3 minutes. The reproducibility was found to be 8.04% (RSD) for good recovery. The test strip has been successfully applied to detect formaldehyde in tofu samples, and the results show in good agreement with the Nash method using UV/vis spectrophotometry.

A sensitive and selective colorimetric method has been developed for detection of Al3+ ion using 4-benzoyl pyrazolone-functionalized gold nanoparticles (BMPBP-AuNPs) as novel colorimetric probes. The BMPBP-AuNPs were characterized by UV-visible spectrometry and transmission electron microscopy (TEM). It was found that the addition of the Al3+ ions led to a rapid aggregation of the BMPBP-AuNPs, which changed the color of the mixture from red to blue. Furthermore, there was a shift in the characteristic surface plasmon resonance (SPR) peak from 524 to 650 nm of BMPBP-AuNPs, which confirmed that a good linear relation (R2 = 0.9935) was present between the absorption ratio of 524 and 650 nm. Also, the assay detected the Al3+ ion concentrations in the linear range 0-12 ppm with the detection limit is 0.05 ppm. Finally, the synthesized BMPBP-AuNPs were successfully used as a colorimetric sensor for the selective and sensitive detection of the Al3+ ions in water samples.

This work presented synthesis of new pyrazolone derivatives and their cytotoxicity assay. The synthesis of pyrazolone derivatives have been achieved using condensation of 2-hydrazinyl methyl-1H-benzoimidazole (H1) with ethylbenzoylacetate in presence of ethanol, which in turn, yielded 1-(benzoimidazole-2-yl)methyl-3-phenyl-1, 4-dihydropyrazole-5-one (BPP). Then, it has reacted with diazonium solution in ethanol and benzoyl chloride in hot dioxin to give 4-azo pyrazolone (BMPAP) and 4-acyl pyrazolone (BMPBP) respectively. The newly synthesized compounds were characterized by FT-IR, 1H NMR and13C NMR. The cytotoxicity assay of the BPP, BMPAP and BMPBP on human breast cancer cells (MCF7) demonstrated their killing ability similar with naturally occurring toxins or immune-mediator cells. The cytotoxicity test was performed using MTT assay (3-[4, 5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). Cell culture with the concentration of 2�104 cells/ml was prepared and was plated (100 �l/well) onto 96-well plates. The diluted ranges of sample extracts were added to each well with identified concentrations: 100, 50, 25, 12.5, 6.25, 3.13 and 1.56 �g/ml and then incubated for 72 hr. MTT solution was added at the end of incubation samples to the cells and continued further for incubation in 3 hr. After solubilization of the purple formazan crystals using DMSO were completed, the Optical Density (OD) was measured using an ELISA reader at a wavelength of 570 nm. The cytotoxicity was recorded as the drug concentration causing 50% growth inhibition of the tumor cells (IC50 value). Overall cytotoxicity test was varied between pyrazolone derivatives with 50% or higher inhibition below 27 �g/ml, and it was considered active and potentially target for further screening. � 2017 American Scientific Publishers All rights reserved.

Determination of Al(III) from aqueous samples using Chrome Azurol S (CAS) as reagent immobilized in polymer inclusion membranes (PIMs) was discussed. The PIMs was prepared using poly (vinyl chloride) (PVC), 2-nitrophenyl octyl ether (2-NPOE) and Aliquat 336 as polymer matrix, solvent and ion carriers respectively. Experimental designs for four factors (weight of PVC, Aliquat 336, 2-NPOE, and the concentration of CAS) were used for the optimization of the membrane fabrication. For this purpose, a two level half factorial design, which involves eight experiments, was adopted. The combination of 200 mg of PVC, 50 mg of Aliquat 336, 50 mg of 2-NPOE and 1 � 10-3 mol/L CAS was found to be the optimum formulation for the preparation of PIMs. Wide dynamic range of Al(III) determination (0.2-50 ppm), better reproducibility within the same batch, good repeatability and photostability with RSD 1.21% and 0.93%, respectively. The calculated t values indicated that there is no significant difference between the two methods at the 95% confidence level and thus there is no bias in the method. � 2014 Elsevier B.V.