Nitric Oxide Detection Using a Corona Phase Molecular Recognition Site on Chiral Single-Walled Carbon Nanotubes.

Semiconducting single-walled carbon nanotubes (s-SWCNT) are structures that fluoresce in the near-infrared region. By coating SWCNT surfaces with polymeric materials such as single-chain DNA, changes in fluorescence emission occur in the presence of reagents. In this way, polymer-coated SWCNT structures allow them to be used as optical sensors for single molecule detection. Especially today, the inadequacy of the methods used in the detection of cellular molecules makes the early diagnosis of diseases such as cancer difficult at the single-molecule level. In this study, the detection of nitric oxide (NO) signals, which are a marker of cancer, was carried out at the single-molecule level. In this context, a sensor structure was formed by coating the 7,6-chiral s-SWCNT surface with ssDNA with different oligonucleotide lengths (AT). The sensor structure was characterized by using UV-vis spectroscopy and Raman spectroscopy microscopy. After formation of the sensor structure, a selectivity library was created using various molecules. As a result of the coating of the SWCNT (7,6) surface with DNA corona phase formation, Raman peaks at 195 and 276 cm-1 were observed to shift to the right. Additionally, the selectivity library results showed that the (AT)30 sequence can be used in NO detection. As a result of the studies using SWCNT (7.6)- (AT)30, the limit of detection (LOD) and limit of determination (LOQ) values of the sensor against NO were found to be 1.24 and 4.13 µM, respectively.

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.

Bimetallic Biogenic Pt-Ag Nanoparticle and Their Application for Electrochemical Dopamine Sensor.

In this study, Silver-Platinum (Pt-Ag) bimetallic nanoparticles were synthesized by the biogenic reduction method using plant extracts. This reduction method offers a highly innovative model for obtaining nanostructures using fewer chemicals. According to this method, a structure with an ideal size of 2.31 nm was obtained according to the Transmission Electron Microscopy (TEM) result. The Pt-Ag bimetallic nanoparticles were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometry (XRD), and Ultraviolet-Visible (UV-VIS) spectroscopy. For the electrochemical activity of the obtained nanoparticles in the dopamine sensor, electrochemical measurements were made with the Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) methods. According to the results of the CV measurements taken, the limit of detection (LOD) was 0.03 µM and the limit of quantification (LOQ) was 0.11 µM. To investigate the antibacterial properties of the obtained Pt-Ag NPs, their antibacterial effects on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria were investigated. In this study, it was observed that Pt-Ag NPs, which were successfully synthesized by biogenic synthesis using plant extract, exhibited high electrocatalytic performance and good antibacterial properties in the determination of dopamine (DA).

Modification of multi-walled carbon nanotubes with platinum-osmium to develop stable catalysts for direct methanol fuel cells.

In the study, a new bimetallic catalyst was synthesized for methanol oxidation using multi-walled carbon nanotube (MWCNT)-supported platinum-osmium (PtOs) nanoparticles (PtOs@MWCNT NPs). The morphological structures of the prepared NPs were examined using different techniques, such as scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical characterization of the synthesized PtOs@MWCNT catalysts, such as chronoamperometry (CA), cyclic voltammetry (CV), scan rate (SR) analysis, cyclic catalytic test, and electrochemical surface area (ECSA) evaluation, were performed in an alkaline medium. From the results obtained, the size of the NPs was found to be 3.12 nm according to the Debye-Schrrer equation, and the MWCNTs were clearly observed by SEM imaging. After the characterization of the prepared nanomaterials, the PtOs@MWCNT catalysts were employed in the methanol oxidation reaction, and a high oxidation current value of 220.86 mA cm-2 was observed. Besides, according to the CA results, the catalyst exhibited high stability for 4000 s, and it was seen that Os metal improved the catalytic activity of the main catalyst. These results show that the PtOs@MWCNT catalyst is highly stable and reusable, and provides high electrocatalytic activity in the methanol oxidation reaction. Moreover, the obtained catalyst gave ideal results in terms of CO tolerance and activity. These data show that the obtained catalyst will provide significant improvement and superior efficiency in fuel-cell applications.

Synthesis and characterization of activated carbon supported bimetallic Pd based nanoparticles and their sensor and antibacterial investigation.

Activated carbon (AC) supported palladium cobalt bimetallic nanoparticles (PdCo@AC NPs) were obtained by green synthesis method using Cinnamomum verum (C. Verum) extract. The obtained NPs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Crystallography (XRD), Transmission Electron Microscope (TEM) and Ultraviolet Visible (UV-VIS) spectroscopy, and the functional groups and morphology of the nanoparticle were elucidated. The resulting particle size was found to be 2.467 nm. NPs were evaluated using Cyclic Voltammetry (CV), Scan Rate (SR), and Differential Pulse Voltammetry (DPV) techniques for potential dopamine sensors application. According to the obtained DPV results, Limit of Detection (LOD) and Limit of Quantitation (LOQ) values are found to be 5.68 pM and 17.21 pM, respectively. It was also observed that AC supported PdCo nanoparticles obtained from C. verum extract sensed dopamine quite well. Besides, to examine the antibacterial properties of NPs, antibacterial analyzes were performed with Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus). It was observed that it showed good antibacterial properties against gram positive (S. aureus) and gram negative (E. coli) bacteria. The study gave important results in terms of the synthesis of bimetallic NPs using the green synthesis method and their usability in different areas. With this study, it was observed that a good antibacterial dopamine sensor were obtained with the successful biogenic synthesis of AC supported PdCo bimetallic NPs.

Synthesis and application of AuNi@AC nano adsorbents for the removal of Maxilon Blue 5G azo dye from aquatic mediums.

In this research, gold-nicel supported on activated carbon (AC) nanoadsorbent (AuNi@AC) synthesized by following a series of physicochemical procedures was prepared for the removal of Maxilon Blue 5G (MB) which is a cationic textile dye. Experimental studies based on parameters specifically pH, contact time, nano catalytic adsorbent particle, initial MB dye concentration and temperature effect were conducted in aqueous solutions in a batch system. AuNi@AC nanoadsorbents (NAs) reached the equilibrium in 30 min under optimum conditions in adsorption of the dye. The pseudo-first, second-order, and intra-particle diffusion models were tested to evaluate a the experimental results. Adsorption kinetics were found to be represented by the pseudo-second-order model, and the maximum adsorption capacity (qmax.) was calculated to be 542.90 mg/g (or 2.041 mmol/g). The synthesized magnetic AuNi@AC nanoadsorbent showed a high-efficiency reusability effect of about 64% after five reuse runs. Also, thermodynamic function parameters such as activation energy (Ea), Gibbs free energy (ΔG *), and entropy (ΔS *) were investigated in the sorption study. After all evaluation of data, it was concluded that the novel AuNi@AC nanoadsorbent could be considered as an effective support material for the removal of various organic pollutants in aquation solution especially for the removal of MB.

High-efficiency application of CTS-Co NPs mimicking peroxidase enzyme on TMB(ox).

In this study, analytical studies of Chitosan-Cobalt(II) (CTS-Co(II)) nanoparticles (CTS - Co NPs) by mimicking horseradish peroxidase (HRP) were evaluated. In the applications, it was observed that CTS-Co NPs 3,3' 5,5' tetramethylbenzidine (TMB) oxidized in the presence of hydrogen peroxide (H2O2). The required CTS-Co NPs were synthesized at 50 °C in 30 min and characterized using Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and X-ray photon spectroscopy (XPS) was done. CTS-Co NPs were studied to develop a selective TMB biosensor on TMB(ox) substrate. The synthesized CTS-Co NPs formed a catalytic reaction with 30% 0.2 mM H2O2 on 0.2 M TMB substrate. After the catalytic reaction, sensitive signals were obtained from the desired biosensor. Electrochemical measurements were taken as low limit of 10 mg and a high limit of 20 mg for the determination of CTS-Co NPs to TMB(ox). In the microplate study; The sensors were applied on 1.5 µg and 3 µg CTS-Co NPs TMB(ox) substrate, respectively. CTS- Co NPs; for TMB(ox) determination, optical density (OD) measurement was taken as a low limit of 1.5 µg and a high limit of 3 µg. Electrochemical applications of particles and microplate reader results were compared with horseradish peroxidase (HRP) enzyme for sensor properties. According to the data obtained, it was observed that it behaved similarly to the CTS-Co NPs peroxidase enzyme. This work presents innovations for nanoparticle extraction and sensor study from chitosan and other naturally sourced polymers.

Green synthesis, characterization and bioactivity of biogenic zinc oxide nanoparticles.

In this study, we tried to enlighten the structure of zinc oxide nanoparticles (ZnO NPs) obtained from Thymbra Spicata L. plant by using green synthesis method in various ways. Some properties of zinc oxide nanoparticles were determined by using the characterization methods that scanning electron microscopy (SEM), Energy Dispersive X-ray analysis (EDX), fouirer transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet visible spectroscopy (UV-Vis) spectroscopy methods. The detected Zn nanoparticle sizes were determined to be between 6.5 nm and 7.5 nm. In addition to these studies, we investigated the antimicrobial effects of zinc oxide nanoparticles obtained by green synthesis against some pathogens. According to the results, it was seen that zinc oxide nanoparticles formed zones with a diameter of 16.3 mm, 10.25 mm, 13 mm and 10.2 mm, respectively, against Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25952, Pseudomonas aeruginosa ATCC 27853 bacteria and Candida albicans ATTC 90028 fungus, respectively. However, the radical quenching activity (DPPH) of the nanoparticles (Ts-ZnONP (79.67%)) was determined to be quite good compared to the positive control BHA. In addition, it is seen that the protective effect of ZnO NPs against DNA damage increases depending on the concentration. At a concentration of 100 mg/L, the DNA damage inhibitory effect was found to be maximum. In line with the comprehensive results, it was determined that the zinc oxide nanoparticles obtained with the green synthesis method have the potential of use in a wide variety of fields.

A novel bio-solid phase extractor for preconcentrations of Hg and Sn in food samples.

An ecofriendly preconcentration method was developed based on the use of Geobacillus galactosidasius sp. nov immobilized on Amberlite XAD-4 as an adsorbent for the preconcentrations of Hg and Sn. SEM-EDX performed for the investigation of surface functionality and morphology. The detailed investigations of factors such as pH of the solution, flow rate, interfering ions and sample volume have been thanks to the optimization of the pre-concentration system. The optimum pHs were found as 5.0-7.0 for Hg and Sn and also the optimum flow rates were determined as 2 mL min-1 for recovery of Hg and Sn. Under the best experimental conditions, limits of detections (LOD) were found as 0.53 ng mL-1 for Hg and 0.27 ng mL-1 for Sn. RSDs were calculated as 8.2% for Hg and 6.9% for Sn. The process was validated to use certified references (fish samples). ICP-OES was used to measure the levels of Hg and Sn in various real meal patterns after the devised technique was used. Concentrations of Hg and Sn were quantitively measured on gluten-free biscuit, flour, rice, Tuna fish, meat, chicken meat, potato, chocolate, coffee, tap water, energy drink and mineral water samples with low RSD. The developed method emerges as an innovative technology that will eliminate the low cost and toxic effect.