Hydrothermal synthesis of B, S, and N-doped carbon quantum dots for colorimetric sensing of heavy metal ions.

In this study, glucose was used as the carbon source to synthesize carbon quantum dots (CQDs) and also aimed to synthesize CQDs doped with heteroatoms such as sulphur, nitrogen, and boron to enhance their functionality. The obtained material has been characterized by several techniques. According to FL analysis, the highest peaks for CQD, N-CQD, B-CQD, and S-CQD were determined as 432 nm (ex 350), 425 (ex 350), 430 nm (ex 340 nm), and 436 nm (ex 340 nm), respectively. FTIR spectra showed different characteristic peaks for CQD, and the FTIR results show that CQDs have a unique structure. According to TEM analysis, the morphology of all CQDs was found to be spherical and monodisperse with average sizes in the range of 5-7 nm. The characterization results of CQDs show that the addition of heteroatoms changes the properties of CQDs. The synthesized CQDs were also tested as colorimetric sensors for the detection of heavy metals. It was observed that CQDs detected Fe3+ metal ions, B-CQD and S-CQD detected Fe3+ and Ag+ metal ions, and N-CQDs detected Ca2+ metal ions. Sensor studies were performed for all CQDs and linear plots were obtained against metal concentrations in the range of 0.06-1.23 µM. LOD values for CQD, N-CQD, S-CQD, and B-CQD were calculated as 0.187 µM (Fe3+), 0.391 µM (Ca2+), 0.224 µM (Fe3+)-0.442 µM (Ag+), and 0.182 µM (Fe3+)-0.174 µM (Ag+), respectively. The results show that the addition of B, N, and S atoms to CQDs plays a role in the improvement and modification of colorimetric sensor properties and has the potential to be used in sensor applications for the detection of heavy metals in areas such as the environment and health.

Bi-doped BaBiO3 (x = 0%, 5%, 10%, 15%, and 20%) perovskite oxides by a sol-gel method: comprehensive biological assessment and RhB photodegradation.

The BaBiO3 (BBO) perovskite oxide was prepared via a sol-gel method with different concentrations of Bi nitrate and examined as a photocatalyst for RhB degradation under sunlight, and its antioxidant and antibacterial activities were examined. X-ray diffraction (XRD) indicated the formation of a BaBiO3-BaCO3 (BBO-BCO) binary composite. For the degradation of RhB under solar radiation, high photocatalytic activity (73%) was observed. According to the antibacterial activity study, the addition of Bi enhanced the antibacterial activity of the resulting material against both Gram-positive and Gram-negative microorganisms. The Bi%-BBO (Bi 20%) inhibited 96.23% S. aureus. 10% Bi-BBO as an antioxidant agent had the most efficacious IC50 value of 2.50 mg mL-1. These results seem to suggest that BBO-BCO is a promising catalytic material with potential application in the fields of catalysis and medicine.

Colorimetric sensor based on biogenic nanomaterials for high sensitive detection of hydrogen peroxide and multi-metals.

Hydrogen peroxide (H2O2) and heavy metals, which are among the wastes of the industrial sector, become a threat to living things and the environment above certain concentrations. Therefore, the detection of both H2O2 and heavy metals with simple, low-cost, and fast analytical methods has gained great importance. The use of nanoparticles in colorimetric sensor technology for the detection of these analytes provides great advantages. In recent years, green synthesis of nanomaterials with products that can be considered biowaste is among the popular topics. In this study, silver/silver chloride nanoparticles (Ag@AgCl NPs) were synthesized using the green synthesis method as an eco-friendly and cheap method, the green algae extract was used as a reducing agent. The characterization of Ag@AgCl nanoparticles and green algae extract was carried out with several techniques such as Transmission Electron Microscopy (TEM), UV-Visible spectrometry (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction patterns (XRD) methods were used for characterization. According to TEM analysis, the Ag@AgCl NPs typically spherical in form and range in size from 4 to 10 nm, and UV-vis showed the formation of surface plasmon resonance (SPR) of the Ag@AgCl between 400 and 450 nm. In addition, its activity as a colorimetric sensor for hydrogen peroxide (H2O2) and multi-metal detection was evaluated. Interestingly, Ag/AgCl NPs caused different color formations for 3 metals simultaneously in the sensor study for heavy metal detection, and Fe3+, Cu2+, and Cr6+ ions were detected. The R2 values for H2O2, Fe3+, Cu2+, and Cr6+ were 0.9360, 0.9961, 0.9787, and 0.9625 the limit of detection (LOD) was 43.75, 1.69, 3.18, and 5.05 ppb (ng/mL), respectively. It was determined that Ag@AgCl NPs have the potential to be used as a colorimetric sensor for the detection of H2O2 and heavy metals from wastewater.

Microwave-assisted synthesis of Vulcan Carbon supported Palladium-Nickel (PdNi@VC) bimetallic nanoparticles, and investigation of antibacterial and Safranine dye removing effects.

As an alternative to antibiotics, nanoparticles (NPs) are increasingly being used for targeting bacteria. Nanotechnology holds great potential in the treatment of bacterial infections. Although the mechanisms of antibacterial activity of NPs are not fully understood, widely accepted explanations include oxidative stress induction, metal ion release, and non-oxidative processes. Several simultaneous gene changes would be required in the bacterial cell, making it difficult for bacterial cells to develop resistance to NPs. One important application of nanoparticles is in dye removal. Nanoparticle structures can be utilized effectively as adsorbents due to their reduced size and increased surface area, by combining noble metals, Palladium-Nickel (Pd-Ni), with a carbon structure known as Vulcan Carbon (VC), it is anticipated that the consumption of precious metals can be reduced while benefiting from the enhanced properties of the bimetallic structure. The PdNi@VC structure was synthesized using the microwave synthesis technique. Characterization techniques such as Transmission Electron Microscope (TEM) and X-Ray diffraction (XRD) were employed to confirm the formation of the bimetallic structure. According to the Debye-Scherrer equation, the size is 2.74 nm. In addition, photodegradation assays using simulator solar radiation yielded 67% efficacy against Safranine dye. In addition, The PdNi@VC had a high percentage of bacterial inhibition at the concentration of 200 g/ml against Staphylococcus aureus (S.aureus), and Escherichia coli (E.coli). This study focuses on the synthesis of bimetallic nanoparticles for antibacterial applications and investigates their effectiveness in dye removal from wastewater. The obtained results provide valuable insights for the implementation of innovative methods in these areas.

Facile bio-fabrication of ZnO@AC nanoparticles from chitosan: Characterization, hydrogen generation, and photocatalytic properties.

In this work, activated carbon-supported zinc oxide nanoparticles (ZnO@AC NPs) were studied using the thermal synthesis method. The activated carbon-supported zinc oxide catalyst was characterized by UV-Vis spectrometry techniques, Fourier Transform Infrared Spectrophotometer (FTIR), Transmissive electron microscopy (TEM), and X-ray diffraction (XRD) methods. XRD characterization measurements showed that the average size of the crystal NPs was 6.89 nm. According to the TEM analysis results, the nanoparticles' average size was 11.411 nm, and the particles had a spherical structure. The catalytic properties of the synthesized material were determined using the sodium borohydride methanolysis reaction. A kinetic study was performed regarding the effects of temperature, catalyst, and substrate concentration on the methanolysis reaction. Reusability experiments showed that the catalyst had excellent catalytic activity (85%), stability, and selectivity. As a result of the kinetic study, activation energy, enthalpy (ΔH), entropy (ΔS), and hydrogen production rate activation parameters were found to be 42.52 kJ/mol, 39.98 kJ/mol, -181.42 J/mol.K, 1257.69 mL/min. g, respectively. Also, the photocatalytic activity of ZnO@AC NPs was analyzed against Rhodamine B (RhB) dye, and the maximum degradation percentage was observed to be 76% at 120 min. This study aimed to develop the ZnO@AC NPs into an efficient photocatalyst to prevent industrial wastewater pollution and as a catalyst for hydrogen synthesis as an alternative energy source.

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.

An environmental approach for the photodegradation of toxic pollutants from wastewater using Pt-Pd nanoparticles: Antioxidant, antibacterial and lipid peroxidation inhibition applications.

BACKGROUND: Green synthesis is an effective and friendly method for the environment, especially in recent years has been used in many areas. It finds application opportunities in many fields such as physics, chemistry, electronics, food, and especially health and is the subject of intensive studies in this field. OBJECTIVES: The synthesized Pt-Pd NPs were aimed to be used as a bio-based photocatalyst under sunlight to prevent wastewater pollution. In addition, it is aimed to use Pt-Pd NPs as biological agents in different applications in the future. METHODS: In this study, the platinum-palladium nanoparticles were synthesized by the extract of Hibiscus sabdariffa, the characterization of the nanoparticles was carried out by different methods (ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), infrared transform spectroscopy atomic force microscopy (AFM), and ray diffraction (XRD) analysis). And we discussed several different parameters related to human health by obtaining platinum-palladium bimetallic nanoparticles (Pt-Pd NPs) with a green synthesis method. These parameters are antioxidant properties (total phenolic, flavonoid, and DPPH scavenging activity), antibacterial activity, and lipid peroxidation inhibition activity. Gallic acid was used as standard phenolic, and quercetin was used as standard flavonoid reagents. The newly synthesized Hibiscus sabdariffa mediated green synthesized Pt-Pd NPs were compared with gram-positive and gram-negative bacteria, the high antibacterial activity was shown by gram-positive bacteria. The photodegradation of Pt-Pd NPs was carried out against MB dye for 180 min. RESULTS: TEM results show that the average size of Pt-Pd NPs is around 4.40 nm. The total amount of phenolic compounds contained in 0.2 mg/ml of Pt-Pd NPs was equivalent to 14.962 ± 7.890 µg/ml gallic acid and the total amount of flavonoid component was found to be equal to 28.9986 ± 0.204 µg/ml quercetin. Hibiscus sabdariffa mediated green synthesized Pt-Pd NPs was found to have very effective for lipid peroxidation inhibition activity in the FeCl2-H2O2 system. The maximum DPPH scavenging activity was determined as 97.35% at 200 µg/ml. The photocatalytic activity of Pt-Pd NPs was analysed against Methylene blue (MB) and the maximum degradation percentage was observed to be 83.46% at 180 min. CONCLUSIONS: The biogenic Pt-Pd NPs showed a high effective photocatalytic and biological activity.

Biosynthesis of Ag-Pt bimetallic nanoparticles using propolis extract: Antibacterial effects and catalytic activity on NaBH4 hydrolysis.

The critical environmental issues of antibiotic resistance and renewable energies supply urge researching materials synthesis and catalyst activity on hydrogen production processes. Aiming to analyse the antibacterial effect of platinum-silver (Ag-Pt) nanoparticles (NPs) and the catalyst effect on NaBH4 hydrolysis that can be used for hydrogen generation technology, in this work, Ag-Pt NPs were prepared using aqueous propolis extract. Various methods were used for the characterization (Uv-vis Spectroscopy, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM) and X-ray diffraction Spectroscopy (XRD)). The antimicrobial activity of Ag-Pt bimetallic nanoparticles was evaluated in vitro by the microdilution method against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Staphylococcus epidermidis, and Serratia marcescens. The results confirmed the antimicrobial activity of bimetallic NPs Ag-Pt concentrations of (25, 50, and 100 µg/ml). A concentration of 100 µg/ml showed low bacterial viability varying between 22.58% and 29.67% for the six tested bacteria. For the catalyst activity on NaBH4 hydrolysis, the results showed high turnover factor (TOF) and low activation energy of 1208.57 h-1 and 25.61 kJ/mol, respectively, with high hydrogen yield under low temperature. Synthesized Ag-Pt NPs can have great potential for biological and hydrogen storage applications.