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In this study, we have prepared anatase titanium (IV) oxide warped reduced graphene oxide nanocomposites (TiO2-rGO NC) using ultrasonic methodology. The morphology of the TiO2-rGO NC was studied using FESEM and TEM. In addition, XRD, Raman, thermogravimetric analysis (TGA) and XPS are used to analyze the crystallinity and chemical composition of the TiO2-rGO NC. We have also investigated the electrochemical behavior of the as-prepared NCs with electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and different pulse voltammetry techniques (DPV). The TiO2-rGO NC modified electrode shows the lower charge transfer resistance (Rct) of 62.87 Ω. Next, the glassy carbon electrode (GCE) was modified with sonochemically prepared TiO2-rGO NC and used to determine the electrocatalytic reduction of nitrofurazone (NTF). Thus, the proposed sensor established the wider covering range (WCR) of 0.01 to 380 µM and an excellent detection limit of 2.28 nM. Finally, the TiO2-rGO NC/GCE was applied to determine the NTF in real samples, including crayfish and human blood serum samples, which acquired good found and recovery values. [ABSTRACT FROM AUTHOR]

Three natural extracted oils from Citrus reticulata peels, C. aurantifolia leaves, and Linum usitatissimum (linseeds) were used as antifungal agents against the growth of Aspergillus flavus and Penicillium chrysogenum. The following main compounds (determined via gas chromatography--mass spectrometry) were found. The essential oil (EO) from C. aurantiifolia leaves contained limonene (22.96%), geranyl acetal (13.53%), and geraniol acetate (13.33%); the n-hexane oil from C. reticulata peels contained methyl-13-cyclopentyltridecanoate (16.74%), and D-limonene (16.06%); and linseed oil contained linoleic acid (27.36%), and oleic acid (19.01%). The inhibition of fungal growth significantly was reached 100% against A. flavus at all tested C. aurantifolia leaf EO concentrations and at a concentration of 2000 µL/mL for linseeds oil. The growth inhibition reached 100% against P. chrysogenum with C. aurantifolia leaf EO concentrations of 125-2000 µL/mL. Citrus reticulata peel EO had 100% growth inhibition of P. chrysogenum at concentrations of 2000 µL/mL and 1000 µL/mL, while linseeds oil had 100% growth inhibition at 2000 µL/mL. Thermogravimetric analysis showed that C. aurantifolia EO yielded the greatest thermal stability and color change protection to cotton pulp, while linseed oil was found to protect wood pulpbased and historical papers. [ABSTRACT FROM AUTHOR]

Background: early blight disease caused by Alternaria solani is one of the most destructive diseases of the tomato, reducing tomato production globally. Methods: four fungal isolates were collected from four tomato cultivars and identified through morphological characterization and polymerase chain reaction (PCR) amplification of the internal transcript spacer (ITS) region. Plectranthus neochilus and Parthenocissus quinquefolia methanol extracts and the bioagents Trichoderma viride and Pseudomonas fluorescens were used as antifungal agents in vitro and in vivo and compared with chlorothalonil, a reference chemical fungicide. HPLC analysis of the plant extracts was used to identify the main flavonoid compounds, namely, rutin and myricetin. Results: molecular characterization showed that the fungal isolates belonged to A. solani. The results of in vitro antifungal activity studies revealed that chlorothalonil, at a concentration of 2500 mg/L, showed the highest inhibition percentage of fungal growth (IPFG) against A. solani (84.4%), followed by the bioagents T. viride and P. fluorescens, with IPFG values of 72.9% and 67.9%, respectively. Moderate to weak activity was found against A. solani when P. neochilus and P. quinquefolia extracts were applied at a concentration of 2500 mg/L, with an IPFG value of 54% for both extracts. The results of in vivo spray application showed that T. viride and chlorothalonil, as well as P. fluorescens, significantly reduced the disease index of early blight, and followed by the P. neochilus and P. quinquefolia extracts. By HPLC, the flavonoid compounds rutin and myricetin were identified in P. neochilus (leaf) with amounts of 2429.60 and 75.92 mg/100 g of extract, and in P. quinquefolia (fruit), with amounts of 1891.60 and 241.06 mg/100 g of extract, respectively. Conclusions: the results of the bioactivity of plant extracts and the bioagents indicate a vital role as antifungal activity against A. solani. [ABSTRACT FROM AUTHOR]

• Carbazoles used as corrosion inhibitors for mild steel. • Electrochemical measurements revealed mixed-type inhibitors. • SEM images reveal formation of protective film by inhibitors on steel surface. • Quantum chemical calculations are in good agreement with experimental results. Corrosion inhibition potentials of 3,6-dibromo-9-phenylcarbazole (DBPCZ) and 3(9H-carbazol-9-yl)-1,2-propanediol (CZPD) were investigated for 1 M HCl solution and microbiologically influenced corrosion (MIC) of mild steel using electrochemical and gravimetric methods, respectively. Potentiodynamic polarization results showed that DBPCZ and CZPD are mixed-type inhibitors (with predominant cathodic influence) of mild steel corrosion in 1 M HCl. DBPCZ and CZPD exhibited 81% and 87% inhibition efficiencies respectively as revealed by polarization measurements. Adsorption of DBPCZ and CZPD molecules on the steel surface in 1 M HCl was best defined by Frumkin adsorption isotherm. Uninhibited corrosion of steel by sulphate-reducing bacteria (SRB), which proceeded at the rate of 0.02 g cm−2 day−1 was subdued by 98% in the presence of 300 ppm of DBPCZ. Quantum chemical calculations suggested that the major molecular fragment in DBPCZ and CZPD molecules involved in donor-acceptor exchanges with Fe atom in mild steel is the carbazole ring. Monte Carlo simulations showed that the carbazole ring of the inhibitor molecules approaches Fe(110) in a near-flat orientation with predicted adsorption energies (E ads) of -114.24 kcal/mol and -119.85 kcal/mol for DBPCZ/Fe(110) and CZPD/Fe(110) respectively. [ABSTRACT FROM AUTHOR]