A comparative study of iron nanoflower and nanocube in terms of antibacterial properties.

It is known that heavy metal containing nanomaterials can easily prevent the formation of microbial cultures. The emergence of new generation epidemic diseases in the last 2 years has increased the importance of both personal and environmental hygiene. For this reason, in addition to preventing the spread of diseases, studies on alternative disinfectant substances are also carried out. In this study, the antibacterial activity of nanoflower and nanocube, which are easily synthesized and nanoparticle species containing iron, were compared. The antioxidant abilities of new synthesized NF@FeO(OH) and NC@α-Fe2O3 were tested by DPPH scavenging activity assay. The highest DPPH inhibition was achieved with NC@α-Fe2O3 as 71.30% at 200 mg/L. NF@FeO(OH) and NC@α-Fe2O3 demonstrated excellent DNA cleavage ability. The antimicrobial capabilities of NF@FeO(OH) and NC@α-Fe2O3 were analyzed with micro dilution procedure. In 500 mg/L, the antimicrobial activity was 100%. In addition to these, the biofilm inhibition of NF@FeO(OH) and NC@α-Fe2O3 were investigated against S. aureus and P. aeruginosa and it was found that they showed significant antibiofilm inhibition. It is suggested that additional studies can be continued to be developed and used as an antibacterial according to the results of the nanoparticles after various toxicological test systems. Supplementary Information: The online version contains supplementary material available at 10.1007/s13204-023-02822-5.

Preconcentrations of Pb(II), Ni(II) and Zn(II) by solid phase bio-extractor using thermophilic Bacillus subtilis loaded multiwalled carbon nanotube biosorbent.

An alternative biotechnological solid phase bio-extraction (SPE) method was developed. Bacillus subtilis loaded multiwalled carbon nanotube was designed and used as biosorbent for the preconcentrations of Pb(II), Ni(II), and Zn(II). The experimental parameters such as sample flow rate, pH of sample solution, amounts of Bacillus subtilis and multiwalled carbon nanotube, volume of sample solution and reusability of column which affects the analytical characteristics of the SPE method were investigated in details. Surface structures were examined by using FTIR, SEM. The best pH was determined as 5.0 and the percentages recoveries of Zn(II), Ni(II), and Pb(II) were determined as 99.1%, 98.7%, and 96.2%, respectively, at a flow rate of 3 mL/min. In this study, in which the profitable sample volume was determined as 400 mL and the amount of multiwalled carbon nanotube (MWCNT) as 50 mg. It was also observed that the column had a significant potential to preconcentrate Zn(II), Ni(II), and Pb(II) even after 25 reuses. The biosorption capacities for Zn(II), Ni(II) and Pb(II) were calculated as 39.67 mg/g, 45.98 mg/g and 51.34 mg/g respectively. The LOD values were calculated as 0.024 ng/mL for Pb(II), 0.029 ng/mL for Ni(II), and 0.019 ng/mL for Zn(II). The linear range was detected as 0.25-25 ng/mL. The concentrations of Pb(II), Ni(II), and Zn(II) in a variety of real food samples were determined by using developed method after application of certified reference sample.

Coupling wastewater valorization with sustainable biofuel production: Comparison of lab- and pilot-scale biomass yields of Chlorella sorokiniana grown in wastewater under photoautotrophic and mixotrophic conditions.

Microalgae are the important biofuel precursors and their economic cultivation can be boosted under mixotrophic (MT) conditions while employing different industrial wastewaters containing organic carbon. In the current research, the quantitative analysis of microalgal biomass production under MT and photoautotrophic (PT) cultivation conditions both at lab and pilot scales was studied. For the purpose, a pre-identified microalgal species Chlorella sorokiniana was cultivated mixotrophically and photoautotrophically at lab and pilot scales. Artificially prepared wastewater containing 2% (w/v) sugarcane molasses was used for MT cultivation. However, for PT cultivation, atmospheric CO2 was the only carbon source. After 15 days of aerobic incubation, microalgal biomass was harvested and analyzed for biomass productivity. Cultivation conditions and cultivation scale posed significant and non-significant impact, respectively on biomass productivities. However, biomass productivity was comparatively higher for the biomass raised under MT conditions at lab scale. The recorded values of biomass productivity were 88.75 ± 9.51 and 127.68 ± 7.91 mg L-1 d-1 for the biomass raised at lab scale under PT and MT conditions, respectively. Pilot-scale cultivation depicted biomass productivities as 83.49 ± 7.87 and 124.88 ± 3.76 mg L-1 d-1 under PT and MT conditions, respectively. High biomass production under MT conditions may suggest the elevated production of biofuels from microalgae. Future studies on biomass production while utilizing different industrial wastewaters at pilot scale and in open raceway ponds are needed for viable production of microalgae-based fuels.

A Method for Reducing the Singlet-Triplet Energy Gaps of TADF Materials for Improving the Blue OLED Efficiency.

We have successfully synthesized a series of blue thermally activated delayed fluorescence emitters, BPy-pC, BPy-pTC, BPy-p2C, and BPy-p3C, bearing a 4-benzoylpyridine core as the electron-accepting unit and carbazolyl, tert-butylcarbazolyl, dicarbazolyl, and tercarbazolyl groups as the electron-donating units, respectively. The density functional theory calculation shows that all of the compounds have their lowest unoccupied molecular orbitals on the benzoylpyridine moiety. However, the highest occupied molecular orbital (HOMO) of BPy-p3C is widely dispersed to the whole tercarbazolyl group, while the HOMOs of BPy-pC and BPy-pTC are mainly on the carbazolyl and extended to the phenyl ring. As a result, ΔEST is reduced from 0.29 eV for BPy-pC to 0.05 eV for BPy-p3C, and the organic light-emitting diodes using these materials as dopants emit blue light and their maximum external quantum efficiencies (EQEs) increase from 4.2% to 23.9% for BPy-pC and BPy-p3C, respectively. The EQE of the BPy-p3C-based device increases 2 times more than that of the BPy-pTC-based device without a significant change in the color coordinates.

A New Molecular Design Based on Thermally Activated Delayed Fluorescence for Highly Efficient Organic Light Emitting Diodes.

Two benzoylpyridine-carbazole based fluorescence materials DCBPy and DTCBPy, bearing two carbazolyl and 4-(t-butyl)carbazolyl groups, respectively, at the meta and ortho carbons of the benzoyl ring, were synthesized. These molecules show very small ΔEST of 0.03 and 0.04 eV and transient PL characteristics indicating that they are thermally activated delayed fluorescence (TADF) materials. In addition, they show extremely different photoluminescent quantum yields in solution and in the solid state: in cyclohexane the value are 14 and 36%, but in the thin films, the value increase to 88.0 and 91.4%, respectively. The OLEDs using DCBPy and DTCBPy as dopants emit blue and green light with EQEs of 24.0 and 27.2%, respectively, and with low efficiency roll-off at practical brightness level. The crystal structure of DTCBPy reveals a substantial interaction between the ortho donor (carbazolyl) and acceptor (4-pyridylcarbonyl) unit. This interaction between donor and acceptor substituents likely play a key role to achieve very small ΔEST with high photoluminescence quantum yield.

Rh(III)-catalyzed synthesis of 1-substituted isoquinolinium salts via a C-H bond activation reaction of ketimines with alkynes.

An efficient synthesis of highly substituted isoquinolinium salts from ketimines and alkynes via a Rh(III)-catalyzed C-H bond activation and annulation reaction is described.

Synthesis of Phenanthridinones from N-methoxybenzamides and aryltriethoxysilanes through Rh(III)-catalyzed C-H and N-H bond activation.

An efficient method for the one-pot synthesis of substituted phenanthridinone derivatives from N-methoxybenzamides and aryltriethoxysilanes through rhodium-catalyzed dual C-H bond activation and annulation reactions is described. A double-cycle mechanism is proposed to account for this catalytic reaction. In addition, isotope-labeling studies were performed to understand the intimate mechanism of the reaction.

Ru(II)-catalyzed C-H bond activation for the synthesis of substituted isoquinolinium salts from benzaldehydes, amines, and alkynes.

An efficient method for the synthesis of substituted isoquinolinium salts from benzaldehydes, amines, and alkynes via ruthenium-catalyzed C-H bond activation and annulation in one pot is described.