Preparation of nanostructured photocatalyst ZnSnO3@S-doped g-C3N4 and its use in DB1 dye degradation through photocatalytic ozonation process.

This study aimed to investigate the potential of the photocatalytic ozonation process (PCO) for decolorizing DB1(direct blue) dye, a commonly used dye in the textile industry known for its resistance to removal from wastewater. To address this challenge, a ZnSnO3@S-doped g-C3N4 nano photocatalyst was synthesized using a simple hydrothermal method. In a novel approach, a light/O3/ZnSnO3@S-doped g-C3N4 system was employed for the first time to degrade the DB1 dye. BET analysis indicated that the synthesized catalyst exhibited the fifth type of isotherm, typically associated with materials containing mesopores. Under optimized conditions, the PCO process achieved complete decolorization of 70 ppm DB1 dye within just 15 min at a temperature of 25 °C, a gas flow rate of 2.83 ml/s, and a catalyst dosage of 0.003 g, encompassing both removal and photocatalytic contributions. Importantly, the catalyst demonstrated excellent stability and could be reused up to five times. These findings highlight the promising potential of the light/O3/ZnSnO3@S-doped g-C3N4 system in effectively decolorizing DB1 dye, overcoming its resistance, and addressing an important challenge faced by the textile industry in wastewater treatment. The formative nature of this study provides valuable insights into the development of advanced oxidation processes for efficient dye removal.

Enhancing insecticidal efficacy of Bacillus thuringiensis Cry1Ab through pH-sensitive encapsulation.

Nanotechnology is a promising way to enhance the stability of Bacillus thuringiensis (Bt) insecticidal proteins under environmental conditions. In this work, two emulsions were prepared through the Pickering emulsion technique, stabilized by Cu2+-SQDs/S-CN nanocomposites and by GO nanosheets. In addition, a pH-sensitive polymer was incorporated into these emulsions, allowing the Bt protein, Cry1Ab, to be released in an alkaline pH environment, as it occurs in the lepidopteran pests' gut. The effectiveness of these two nanomaterials in protecting Cry1Ab from degradation, and therefore enhancing its pesticidal activity, was assessed by exposing samples of the purified unprotected protein and encapsulated protein to high-intensity UV light and 40°C temperature treatments. The UV treatment results were evaluated using SDS-PAGE analysis and pointed out that Cry1Ab could be structurally protected by the emulsions. The bioassays with first instar larvae of the lepidopteran pest Ostrinia nubilalis confirm the nanomaterial protection to UV and temperature treatments, i.e., decreasing about half the degradation rate and increasing up to 12-fold the residual activity after UV treatment. Our results indicate that encapsulation could be an effective strategy to improve the effectiveness of Cry1Ab under environmental conditions. KEY POINTS: • Pickering emulsions are effective for solubilized Cry1Ab encapsulation. • Structural and toxicity Cry1Ab properties are enhanced by pH-sensitive encapsulation. • Cu2+-SQDs/S-CN and GO nanomaterials improve the efficacy of Bt insecticides.

Green synthesis of bovine serum albumin/oxidized gum Arabic nanocomposite as pH-responsive carrier for controlled release of piperine and the molecular docking study.

A safe drug carrier was synthesized by albumin (BSA) and oxidized gum arabic (OGA). Piperine (PIP) was loaded into BSA/OGA nanobiocomposites by desolvation method. A set of experiments were designed by considering different contents of OGA (5, 7.5 and 10 mg) and PIP (1 and 2 mg). The presence of the band at 1600-1660 cm-1 in FTIR spectra revealed the successful interaction between OGA and BSA. PIP2-BSA/OGA5 was selected as a suitable carrier due to its smaller size (<300 nm) and higher loading efficiency (1.5 ± 0.2 %). The encapsulation efficiency of PIP into BSA/OGA5 was 57.6 ± 2 %. The average size, polydispersity index and zeta potential of PIP2-BSA/OGA5 were 292 ± 4.4 nm, 0.185 ± 0.03 and - 24.4 ± 1.7 mV, respectively. SEM and TEM images proved the formation of spherical-shaped nanoparticles. The disappearance of endothermic peak belonging to free PIP in DSC thermogram of PIP2-BSA/OGA5 evidenced its encapsulation into carrier. PIP2-BSA/OGA5 exhibited the sustained drug release. The cell viability of MCF-7 cells after 48 h exposure to BSA/OGA5, PIP2-BSA/OGA5 and free PIP was reported 90 %, 40.1 % and 30.6 %, respectively. The molecular docking study reported that the binding affinity of PIP for BSA/OGA nanocomposite was -8.7 kcal/mol indicating the acceptable stability of the prepared drug carrier.

Effective visible-light-driven photocatalytic degradation of fenitrothion by s-gC3N4/Ag-Au bimetallic nanocomposite.

This paper reports on the optimization of fenitrothion photocatalytic degradation in visible light based on Plackett Burman (PB) design and central composite design (CCD) in response surface methodology (RSM). A herbicide routinely used with a negative impact on the environment is fenitrothion, which must be degraded to minimize the impact on the environment. For fenitrothion degradation, Ag-Au bimetallic nanoparticles on the semiconducting s-doped gC3N4 surface were synthesized using the galvanic exchange. The properties of s-gC3N4/Ag-Au bimetallic nanocomposite were confirmed by various methods. Significant factors responsible for fenitrothion photocatalytic degradation were determined using Plackett-Burman (PB) design and were catalyst dosage, initial fenitrothion concentration, H2O2 concentration, pH, and rotational speed. Central composite design (CCD) design was used for further optimization. The optimum conditions for the maximum degradation of fenitrothion (100%) constraints were found to be 100% an amount of H2O2 concentration 60 mM, pH 10, rotational speed 700 rpm. These results showed that s-gC3N4/Ag-Au bimetallic nanocomposite could act as a suitable photocatalyst under visible light in the degradation of fenitrothion. By removing fenitrothion from real water samples, as well as by maintaining its stability and reusability in five successive cycles, the practicality of this nanocomposite was demonstrated.

Ultraviolet protection of Bacillus thuringiensis through microencapsulation with Pickering emulsion method.

An encapsulated formulation of Bacillus thuringiensis (Bt) was produced by the Pickering emulsion technique to improve its activity and stability under UV-A radiation. In this technique latex particles, GO nanosheets, olive oil, ethanol, and water were used to encapsulate Bt in colloidosomes. The protective efficacy of this formulation in protecting Bt subsp. Kurstaki against deactivation by UV-A irradiation was measured, so that spore viability and mortality on Ephestia kuehniella (E. kuehniella) Zeller larvae under UV-A radiation are investigated. According to the results of both tests, encapsulated formulation at a concentration of 0.045% has the highest protection of viability. Hence, colloidosome microcapsule formulations successfully provide good protection against UV radiation.

A novel method for biosynthesis of different polymorphs of TiO2 nanoparticles as a protector for Bacillus thuringiensis from Ultra Violet.

Bacillus thuringiensis (Bt) were used for biosynthesis of amorphous TiO2 converted to distinct polymorphs (anatase, rutile, mix) under different temperature conditions. Characterizations of TiO2 nanoparticles were performed by using X-ray diffraction spectroscopy (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and, energy-dispersive X-ray spectroscopy (EDX) analysis. Stability of five formulations under ultraviolet (UV) radiation with spore viability and mortality test on Ephestia kuehniella Zeller larvae were investigated. TiO2(mix) showed the highest viabilities of 79.76% after exposure to ultraviolet (UVA385 nm), while viabilities of non-protected spores under these conditions were 41.32%. The mortality of TiO2(mix), TiO2(anatase), TiO2(rutile), TiO2(amorphous) and free spore formulations on second-instar larvae of Ephestia kuehniella were 73.76%, 71.24%, 57.12%, 51.32%, and 50.32%, respectively on the 10th day of the experiment. The obtained results suggest that TiO2(amorphous) does not increase Bt resistance, but both phases of TiO2 nanoparticles synthesized (anatase and rutile) through the Bacillus thuringiensis and phase mixture can increase the persistence of Bt to the UV light. Furthermore, the combination of both crystalline phases of TiO2(mix) has the highest performance in improving the Bt resistance.

Noble UV protective agent for Bacillus thuringiensis based on a combination of graphene oxide and olive oil.

The focus of this study is investigating the performance of graphene oxide (GO) in the protective effect of olive oil on Bacillus thuringiensis (Bt) after being exposed to UV radiations. Biological pesticides Bt subsp. Kurstaki is one of the most important biological control agents. We compared the protective effect of two UV protectant; GO and olive oil and also the combination of both, on the stability of the formulation of Bt after exposure to UV radiations. Spore viability was measured for protective effect and bioassay test was performed on the formulations of Bt. The combination of GO and olive oil revealed the highest viabilities of 50.62% after 96 h exposure to UV radiation, while viabilities of free spore, olive oil formulation and GO formulation were 32.54%, 37.19%,and 45.20%, respectively. The mortality of irradiated combination formulation on second-instar larvae Ephestia Kuehniella was 68.89%, while the same parameter for free spore, olive oil formulation and GO formulation were 40%, 46.66%,and 56%, respectively.