Hydrogen production and photocatalytic activities from NaBH4 using trimetallic biogenic PdPtCo nanoparticles: Development of machine learning model

Alloyed Trimetallic Nanocomposite as an Efficient and Recyclable Solid Matrix for Ideonella sakaiensis Lipase Immobilization

In this work, a trimetallic (Ni/Co/Zn) organic framework (tMOF), synthesized by a solvothermal method, was calcinated at 400 and 600 °C and the final products were used as a support for lipase immobilization. The material annealed at 400 °C (Ni-Co-Zn@400) had an improved surface area (66.01 m2/g) and pore volume (0.194 cm3/g), which showed the highest enzyme loading capacity (301 mg/g) with a specific activity of 0.196 U/mg, and could protect the enzyme against thermal denaturation at 65 °C. The optimal pH and temperature for the lipase were 8.0 and 45 °C but could tolerate pH levels 7.0-8.0 and temperatures 40-60 °C. Moreover, the immobilized enzyme (Ni-Co-Zn@Lipase, Ni-Co-Zn@400@Lipase, or Ni-Co-Zn@600@Lipase) could be recovered and reused for over seven cycles maintaining 80, 90, and 11% of its original activity and maintained a residual activity >90% after 40 storage days. The remarkable thermostability and storage stability of the immobilized lipase suggest that the rigid structure of the support acted as a protective shield against denaturation, while the improved pH tolerance toward the alkaline range indicates a shift in the ionization state attributed to unequal partitioning of hydroxyl and hydrogen ions within the microenvironment of the active site, suggesting that acidic residues may have been involved in forming an enzyme-support bond. The high enzyme loading capacity, specific activity, encouraging stability, and high recoverability of the tMOF@Lipase indicate that a multimetallic MOF could be a better platform for efficient enzyme immobilization.

Biohydrogen production via green silver nanoparticles synthesized through biomass of Ulva lactuca bloom

Ulva lactuca is a marine green seaweed. Its bloom based biomass accumulated in the İzmir bay and is collected by local authorities. In this investigation, an alternative solution was proposed to utilize the biomass of U. lactuca to produce biohydrogen via green synthesized silver nanoparticles. According to the results, the optimum conditions related to silver nanoparticle production such as pH, temperature, biomass concentration, silver nitrate concentrations, and incubation time were determined to be 11, 25 °C, 10 mg/mL, 4 mM, and 3 days, respectively. Effective conditions for biohydrogen production such as pH, temperature, agitation rate, and sodium borohydride concentration were found to be 7, 50 °C, 250 rpm and 150 mM, respectively. These parameters are also modelled with an artificial neural network. The data presented here provide recommendations for producing biohydrogen from waste algae and helping reduce carbon emissions for better environment and future.

Bio-Fabrication of Trimetallic Nanoparticles and Their Applications

Nanoparticles are materials whose size is less than 100 nm. Because of their distinctive physical and chemical characteristics, nanoparticles have drawn considerable interest in a variety of fields. Biosynthesis of nanoparticles is a green and environmentally friendly technology, which requires fewer chemical reagents, precursors, and catalysts. There are various types of nanomaterials, out of which trimetallic nanoparticles are receiving considerable interest in recent years. Trimetallic nanoparticles possess unique catalytic, biomedical, antimicrobial, active food packaging, and sensing applications as compared to monometallic or bimetallic nanoparticles. Trimetallic nanoparticles are currently synthesized by various methods such as chemical reduction, microwave-assisted, thermal, precipitation, and so on. However, most of these chemical and physical methods are expensive and toxic to the environment. Biological synthesis is one of the promising methods, which includes the use of bacteria, plants, fungi, algae, waste biomass, etc., as reducing agents. Secondary metabolites present in the biological agents act as capping and reducing agents. Green trimetallic nanoparticles can be used for different applications such as anticancer, antibacterial, antifungal, catalytic activity, etc. This review provides an overview of the synthesis of trimetallic nanoparticles using biological agents, and their applications in different areas such as anticancer, antimicrobial activity, drug delivery, catalytic activity, etc. Finally, current challenges, future prospects, and conclusions are highlighted.

The removal of heavy metal pollution from wastewaters using thermophilic B. cereus SO-16 bacteria

In this study, bioaccumulation, remediation, tolerance, and effects of manganese ions (Mn(II)) and copper ions (Cu(II)) on antioxidant enzymes of thermophilic Bacillus cereus (B. cereus) SO-16 were investigated in detail. The findings of the study showed that Mn(II) was less toxic than Cu(II) to B. cereus SO-16. Moreover, B. cereus SO-16 was exhibited less tolerance to Mn(II) and Cu(II) ions in the liquid medium compared to the solid medium. The growth of bacteria was expressively effective for Mn(II) and Cu(II) concentrations of 2.5 mg/L at 24th h. The highest Mn(II) and Cu(II) bioaccumulation values after 48 h incubation of thermophilic B. cereus SO-16 were measured as 102.04 (24th h) and 87.96 (36th h) metal/dry bacteria weight. The change in morphology and functionality of B. cereus SO-16 after interaction with Mn(II) and Cu(II) was tested using various methods. The results indicated that B. cereus SO-16, a thermophilic bacterium, can be utilized in industrial wastewaters to recover and remediation of toxic metals.

An ultra-sensitive rifampicin electrochemical sensor based on Fe3O4 nanoparticles anchored Multiwalled Carbon nanotube modified glassy carbon electrode

This study aimed to guide future sensor studies against other pharmaceutical drugs by synthesizing Fe₃O₄NPs@MWCNT metallic nanoparticles (NPs). Side damage caused by excessive accumulation of tuberculosis drugs in the body can cause clots in the organs, and cause serious damage such as heart attack and respiratory failure, and threaten human life. Therefore, the development of sensors sensitive to various antibiotics in this study is important for human health. In this study, the sensitivity of Fe₃O₄ NPs to tuberculosis drug (rifampicin) was evaluated by catalytic reaction using bare/GCE, MWCNT/GCE, and Fe₃O₄NPs@MWCNT/GCE electrodes. First of all, Fe₃O₄ NPs were successfully synthesized for the study and MWCNT/GCE and Fe₃O₄ NPs@MWCNT/GCE electrodes were formed with the modification of the MWCNT support material. It was observed that the Fe₃O₄ NPs@MWCNT/GCE electrode gave the highest signal against the other electrodes. The morphological structure of Fe₃O₄ NPs was determined by various characterization techniques such as Transmission Electron Microscopy (TEM), Fourier Transmission Infrared Spectroscopy (FTIR), ultraviolet-visible (UV-Vis), and X-ray differential (XRD) and the obtained NPs were used for sensor studies, and it was observed that the current intensity increased as the scanning speed of each electrode increased in CV and DPV measurements. The average size of Fe₃O₄ NPs was found to be 7.32 ± 3.2 nm. Anodic current peaks occurred in the linear range of 2-25 μM. According to the results obtained from the measurements, the limit of detection (LOD) value was calculated as 0.64 μM limit of quantification (LOQ) 1.92 μM.