Aflatoxins (AFs) are a family of fungal toxins that produced in food and feed by two Aspergillus species (Aspergillus flavus and Aspergillus parasiticus). Several techniques have been reported for AFs detection including high-pressure liquid chromatography, enzyme-linked immunosorbent assay, surface plasmon resonance and recombinant immune blotting assay. But, these methods are disadvantaged because they consumed a long time for analysis; in addition, they required a piece of complicated and expensive equipment. Therefore, developing of inexpensive sensors with high selectivity and sensitivity for detecting of AFs levels without extensive sample preparation has received great attention. Several electrochemical AFs sensors have been reported; however, there is still a need for developing a new, simple and rapid electrochemical AFs sensor. Here, we have developed a new AFs sensor based on Au nanostructures/graphene nanosheets modified ITO substrate that could enhance the Raman effect and the electrochemical conductivity. The modified electrode was prepared based on layer-by-layer electrochemical deposition method. AFs antibody was immobilized onto the Au nanostructures/graphene nanosheets; then it was used as a probe for rapid, simple and cheap detection of AFs level using Raman spectroscopy and electrochemical techniques. Our results demonstrated that the developed system showed a simple, easy and sensitive sensor for monitoring low concentrations of AFB1 with a detection limit of about 6.9 pg/mL, also it allowed the determination of AFB1 in spiked food samples.

Hepatitis C virus (HCV) is a blood-borne virus that causes infectious chronic hepatitis. Egypt has the largest epidemic of HCV in the world, with about 14.7% of the Egyptian population. Thus, HCV, which could cause severe risks for human health including liver failure, becomes a public health concern for Egyptians. Development of highly selective and sensitive biosensors for accurate detection of HCV levels without extensive sample preparation has received great attention. The present work reported on developing a new rapid, highly selective and highly selective HCV-based biosensor for early detection of HCV-RNA extracted from clinical samples. The HCV-based biosensor was constructed by fabrication of gold nanodots/indium tin oxide substrate and followed by immobilization of a specific peptide nucleic acid (as bio-receptors) terminated with thiol group onto gold nanodots/indium tin oxide. The principle of the developed biosensor was based on the selective hybridization between the peptide nucleic acid and the HCV-RNA at the untranslated regions (5′-UTR). Raman spectroscopy and Square wave voltammetry techniques were used to monitor the interaction between the HCV-RNA and the immobilized peptide nucleic acid. The reported HCV-biosensor demonstrated a high capability to detect HCVRNA

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Spectrophotometric techniques has been applied for studying the kinetics and mechanistics between Ag+ and [IrCl6]2− reaction in aqueous acidic solutions at a constant ionic strength of 1.0 moldm−3. The naked eyes observation showed that the brownish color of [IrCl6]2− solution was rapidly vanishing with simultaneous appearance of a new dark-blue color on mixing solution of the oxidant with Ag+ ion electrolyte in either neutral or acidic media. The new color was persisted for a few seconds or minutes depending on the reaction conditions. Then, it began to fading out with time elapsing. This result means that the reaction occurs through two distinct stages. The spectral traces indicated the formation of binuclear intermediate complex at the initial fast stage [Ag+…ClIrCl52−] (with the rate constants k1 = 1.15 × 10−2 dm 3 mol−1 s−1; k−1 = 7.35 × 10−5 s−1, formation constant (K) = 1.56 × 102 dm 3 mol−1 and pseudo first- order rate constant (kobs) = 1.31 × 10−4 s−1 at [IrCl6]2− = 2.2 × 10−4, [H+] = 1.0 mol dm−3 and 30 °C. The initial rapid part was followed by a subsequent slow stage corresponding to the decomposition of the formed binuclear intermediate in the rate-determining step to give rise to the final oxidation products. The formation of such binuclear intermediate was found to be of acid-independent; nature; whereas its decomposition was dependent on the acid concentration with inverse fractional first-order in [H+]. This means that the binuclear decomposition is of acid-inhibition nature. In case of presence of a large excess of [Ag+] over that of [IrCl6]2−, Ir(0) nanoparticles was formed as confirmed by the XRD-spectra and TEM morphology. The kinetic parameters for the formation constants and decomposition rate constants of the binuclear complex have been evaluated and a suitable reaction mechanism for the overall redox reaction is suggested and discussed.

The goal of this study is to investigate the effect of a single dose of ethanol on the developing chick embryo.. Fertilized eggs were divided into five groups; a control group, and the other groups were injected in the air sac, before incubation with a single dose of 100 µl saline solution, 5%, 10% or 15% ethanol in saline solution. Results revealed growth retardation and malformations in different organs. Retinal cells were degenerated and cell death was induced in later stages of development. Levels of lipid peroxidation are significantly increased, levels of nitric oxide are fluctuated between an increase in the 5% ethanol treated group and a decrease in the 10% and 15% ethanol treated groups. Levels of the antioxidants, glutathione and vitamin C are significantly decreased at all doses of ethanol used except for a significant increase of glutathione in case of treatment with 10% ethanol. It is suggested that ethanol might exert its action through slowing down the rate of development during the early stages of incubation (two and four days), and later (six days) the action was probably through cellular damage via releasing free radicals and changing levels of nitric oxide concentration. Thus, findings of the current study demonstrate the direct toxic effects of a single dose of ethanol on developing embryos in general and on the eye in particular. Since all human embryos are vulnerable to any accidental alcohol toxixity, pregnant mothers are required to check up for alcohol abnormalities.

4-Amino-3-methyl-1-phenyl-1H-thieno[2,3-c]pyrazole-5-carboxamide has been synthesized by an innovative method. The aminoamide derivative was gently refluxed with chloroacetyl chloride under neat conditions followed by neutralization with sodium carbonate solution to afford the chloromethyl pyrimidinone compound. The chloromethyl pyrimidinone derivative was converted to the thiol derivative by the reaction with thiourea in ethanol. The thiol compound was alkylated with α-halocompounds such as ethyl chloroacetate, chloroacetone, phenacyl bromide and 2-chloro-4,6-dimethylnicotinonitrile to afford the corresponding S-alkylated compounds. The chemical structures of the newly synthesized compounds were elucidated on the basis of elemental and spectral analyses containing FT-IR, 1H-NMR, and mass spectroscopy

4-Amino-3-methyl-1-phenyl-1H-thieno[2,3-c]pyrazole-5-carboxamide has been synthesized by an innovative method. The aminoamide derivative was gently refluxed with chloroacetyl chloride under neat conditions followed by neutralization with sodium carbonate solution to afford the chloromethyl pyrimidinone compound. The chloromethyl pyrimidinone derivative was converted to the thiol derivative by the reaction with thiourea in ethanol. The thiol compound was alkylated with α-halocompounds such as ethyl chloroacetate, chloroacetone, phenacyl bromide and 2-chloro-4,6-dimethylnicotinonitrile to afford the corresponding S-alkylated compounds. The chemical structures of the newly synthesized compounds were elucidated on the basis of elemental and spectral analyses containing FT-IR, 1H-NMR, and mass spectroscopy

4-Amino-3-methyl-1-phenyl-1H-thieno[2,3-c]pyrazole-5-carboxamide has been synthesized by an innovative method. The aminoamide derivative was gently refluxed with chloroacetyl chloride under neat conditions followed by neutralization with sodium carbonate solution to afford the chloromethyl pyrimidinone compound. The chloromethyl pyrimidinone derivative was converted to the thiol derivative by the reaction with thiourea in ethanol. The thiol compound was alkylated with α-halocompounds such as ethyl chloroacetate, chloroacetone, phenacyl bromide and 2-chloro-4,6-dimethylnicotinonitrile to afford the corresponding S-alkylated compounds. The chemical structures of the newly synthesized compounds were elucidated on the basis of elemental and spectral analyses containing FT-IR, 1H-NMR, and mass spectroscopy

4-Amino-3-methyl-1-phenyl-1H-thieno[2,3-c]pyrazole-5-carboxamide has been synthesized by an innovative method. The aminoamide derivative was gently refluxed with chloroacetyl chloride under neat conditions followed by neutralization with sodium carbonate solution to afford the chloromethyl pyrimidinone compound. The chloromethyl pyrimidinone derivative was converted to the thiol derivative by the reaction with thiourea in ethanol. The thiol compound was alkylated with α-halocompounds such as ethyl chloroacetate, chloroacetone, phenacyl bromide and 2-chloro-4,6-dimethylnicotinonitrile to afford the corresponding S-alkylated compounds. The chemical structures of the newly synthesized compounds were elucidated on the basis of elemental and spectral analyses containing FT-IR, 1H-NMR, and mass spectroscopy

New pyrazolothienopyrimidines were synthesized. The key intermediate 4-aminothieno[2,3-c]pyrazole5-carbonitrile 1 was converted to the chloroacetyl amino derivative 2 followed by nucleophilic substitution and Dimorth rearrangement upon treatment with nitrogen nucleophiles to give the pyrimidinones 3a-c. Treatment of 3a with formaldehyde and with triethyl orthoformate afforded the respective tetracyclic derivatives 4 and 5. Condensation of the amino group in the o-aminocarbonitrile 1 with triethyl orthoformate followed by cycloaddition reaction with hydrazine led to the formation of pyrazolothienopyrimidine 8. Compound 8 was used as a synthetic precursor to heterocyclic compounds comprised of pyrazole, triazole, triazine, and triazepine derivatives.