Ultraviolet-visible Spectrophotometer Research Articles

Green synthesis of highly luminous lemon juice-based carbon dots for antimicrobial assessment and fingerprint detection

Abstract Carbon dots are regarded as a brand new class of nanostructures in the carbonaceous family that have piqued the curiosity of researchers in a wide range of bio applications. This work focuses on the synthesis and characterization of carbon dots, as well as their latent fingerprint detection and antibacterial/antifungal capabilities. Highly luminous carbon dots were prepared by optimizing simple hydrothermal carbonization settings at 180 °C for 12 h using lemon juice as a raw precursor. The resulting product was examined using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffractometery, and ultraviolet–visible spectrophotometer. The as-prepared carbon dots were found to be extremely bright when excited under ultraviolet light (λ = 365 nm). The presence of carbon and oxygen functionalities on the surface of the carbon dots was revealed by infrared spectrocopy. The diffraction pattern confirmed the amorphous structure of the carbon dots, with an average size of 7 nm determined using the Scherrer equation. The surface morphology analysis revealed that the carbon dots exhibited an aggregated form with irregular spherical shapes. The chemical structure examination validated the elemental makeup of the prepared lemon juice-based carbon dots. The detection of latent fingerprints on carbon dots under ultraviolet light yielded positive results. In addition, the obtained carbon dots displayed antifungal and antibacterial activity against tested pathogenic fungal and bacterial strains.

Optimizing Solar Power: The Impact of N719 Dye Concentration on DSSC Efficiency with TiO2 Nanoparticles

Dye-sensitized solar cells (DSSC) are photoelectrochemical, alternative energy source devices that convert light energy into electricity. In this study, DSSC with various concentrations (0.1, 0.5, and 1.0 mM) of N719 dye have been successfully prepared using simple steps. The X-ray diffraction results of the TiO2 film showed that it is polycrystalline with an anatase phase (tetragonal system) having a crystallite size of about 20 nm. The absorbance spectrum of the TiO2 film and N719 dye at various concentrations was recorded by ultraviolet-visible (UV-Vis) spectrophotometer. The bandgap energy of the TiO2 film calculated by Tauc’s formula was ~3.1 eV. The DSSC prepared using the N719 dye concentration of 1 mM achieved the highest conversion efficiency (η) of 0.298 %, respectively. Subsequently, the enhancement in efficiency was ~86 % compared with the conversion efficiency of DSSC prepared with an N719 dye concentration of 0.1 and 0.5 mM.

Gold-nanoparticle associated Deep Eutectic Solution mediates early bio detection of Ovarian Cancer

Gold nanoparticles (AuNPs) have indeed been extensively researched in biological and photothermal therapy applications in recent years. This study aims to enhance the sensitivity of biosensors for early detection of ovarian cancer biomarkers by investigating the efficacy of DES-mediated surface functionalization of AuNPs. Additionally, the impact of DES on the stability and dispersion of AuNPs on SiO2 support is assessed to optimize sensor performance. A simple DES-mediated synthesis method for efficient amine surface functionalization of silicon dioxide (SiO2) to incorporate tiny AuNPs for antibody biosensors. Physical characterization [Scanning Electron Microscope (SEM), Ultraviolet-Visible Spectrophotometer (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), and 3D Profiler] and electrical characterization (Keithley) have been done to determine the functionalization of the modified IDE surface. SEM analysis indicated the resultant nanoparticles have truncated spherical shapes. There is just a peak recorded by UV-Vis at 504-540 nm with AuNPs due to the formation of monodispersed AuNPs. When the conjugation of DES with samples is measured, the curves are identical in form, and the highest peak after conjugation has remained at 230 nm but the SPR absorption peak becomes narrower and moves toward greater wavelengths, indicating the conjugation between the molecules. Furthermore, when the DES is conjugated with AuNPs, 3-Aminopropyltriethoxysilane (APTES), antibody, and protein, the peaks gradually increased and became narrower, where O-H at 3280 cm-1, C-H at 2809 cm-1 and 2933 cm-1, CH2 at 1448 cm-1, CH3 at 1268 cm-1, C-OH at 1048 cm-1 and 1110 cm-1 and C-N+ at 844 cm-1 as analyzed by FTIR. Moreover, it can be observed that the 3D profilometer revealed a few red-colored areas, which are the portion that protrudes from the IDE surface. Based on the findings, it is possible to infer that this immunosensor does have the prospective to be used in clinical investigations for the precise detection of ovarian cancer or other biomarkers. The capacitance, transmittance, and resistivity profiles of the biosensor clearly distinguished between the antibody immobilization and the affinity binding. The presence of a DES-mediated synthetic approach increased the possibility of supporting different metal nanoparticles on SiO2 as the potential platform for biosensor applications.

Green synthesis of iron oxide nanoparticles from extracts of Daucus carota subsp. sativus whole vegetable, peel, pomace, and juice and their application as antibacterial agents and Fenton-like catalysts

Abstract The green synthesis of iron oxide nanoparticles (Fe-NPs) with catalytic and antimicrobial activities from the extracts of different parts of Daucus carota subsp. sativus var. atrorubens Alef. was demonstrated in this study. The extracts of whole vegetable, peel, pomace, and juice acted as a reducing agent for the bio-reduction of Fe3+ into Fe-NPs. The synthesis of Fe-NPs was indicated by surface plasmon peaks within the range of 200–300 nm, as well as characteristic iron oxide bond formation in the region of 400–850 cm−1 using an ultraviolet-visible spectrophotometer and FT-IR spectrophotometer, respectively. The green synthesised Fe-NPs from the whole vegetable and its byproduct extracts had uniform quasi-spherical structures, with average particle sizes of 87.13, 80.95, 103.14, and 86.26 nm from whole vegetable extract, peel extract, pomace extract, and juice, respectively. All synthesised particles exhibited excellent Fenton-like catalytic activities on the discoloration of methylene blue best fitting the pseudo-first order kinetic model for Fe-NPs from whole vegetable extract, pomace extract, and juice and the pseudo-second order kinetic model for Fe-NPs from peel extract. In addition to catalytic activity, Fe-NPs showed antibacterial activity against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The antibacterial effects of Fe-NPs alone and their synergistic effects with antibiotics have been observed in both Gram-positive and Gram-negative bacteria.

Synthesis of Au-Pd-NPs Materials and Application as Electrochemical Sensor of Hydroquinone in Cosmetics

Hydroquinone is a hazardous and toxic chemical often added to cosmetics due to bleaching properties. It is commonly analyzed in cosmetics using expensive and time-consuming instruments, showing the need for a cheap, fast, and sensitive hydroquinone electrochemical sensor. The performance of electrochemical sensor to detect hydroquinone is determined by the working electrode. Therefore, this study aimed to explore the synthesis of Au-Pd-NPs working electrode and application as electrochemical sensor of hydroquinone in cosmetics. Synthesis process was carried out by preparing Au-NPs using banana peel extract (Musa acuminata Colla) as a bioreductor, followed by adding H2PdCl4 solution. Au-NPs nanoparticle was confirmed using Ultraviolet-Visible spectrophotometer, which showed maximum wavelength of 550 nm. The indication of Au-Pd-NPs was shown by the peak at the same wavelength. The FTIR spectrum showed pectin which acted as a bioreductant agent in synthesis of nanoparticles. The results of the TEM image showed that Au-NPs had a spherical shape in the dark field with a diameter of 38.5 ± 3.3 nm and a Pd shell layer around the Au core in the bright field with a diameter of 12.4 ± 2.6 nm. The solid Au-Pd-NPs materials were made into a composite electrode by adding PVC and tetrahydrofuran as solvents. Electrochemical response of Au-Pd-NPs electrode was tested by cyclic voltammetry in ferricyanide and PBS solutions at pH 7.0. Based on CV in the ferricyanide system, it shows that Au-Pd-NPs electrode produces peak oxidation and reduction currents ten times higher than Au-NPs. These data indicate that Au-Pd-NPs are more reactive and sensitive than Au-NPs electrodes. The Au-Pd-NPs electrode was used to analysis the concentration of hydroquinone in cosmetics samples. Electrochemical response showed a linearity (R2) of 0.9935 in concentration range of 0-60 mM, containing 1.12% hydroquinone.

Development of TCS3200 Color Sensor Based on Arduino Uno Microcontroller for Determination of Capsaicin Level in Sauces

A color sensor has been designed to measure the capsaicin level in commercial sauces. This system is designed using a TCS2300 color sensor as an input, and an Arduino Uno microcontroller with Integrated Development Environment (IDE) software as signal conditioning and signal processing. The measurement result will be compared to the standard Ultraviolet-Visible (UV-Vis) spectrophotometer method. The sauce samples were taken using a sampling technique, namely eight samples of sauces circulating in the city of Banda Aceh. The result showed that the levels of capsaicin using the TCS3200 color sensor and UV-Vis spectrophotometer ranged from 5.39 to 22.42 mg/L and 5.58 to 22.64 mg/L, respectively. The linearity obtained in the concentration range of 5.25 mg/L shows a linear calibration curve using the TCS3200 color sensor (R2 = 0.9961) and UV-Vis Spectrophotometer (R2 = 0.9973). Accuracy (% recovery) for the TCS3200 color sensor and UV-Vis spectrophotometer ranged from 98.94 to 106.63%, and 98.13 to 110.2% mg/L, respectively. In the case of interday and intraday relative standard deviation has not more than 2%. Based on the t-test assessment, it shows that the TCS3200 color sensor has no differences statistically in results with UV-Vis Spectrophotometer. These results describe that the TCS3200 color sensor can be an alternative for analyses of capsaicin in sauce samples.

Enhancing the structural and optoelectronic properties of carboxymethyl cellulose sodium filled with ZnO/GO and CuO/GO nanocomposites for antimicrobial packaging applications.

One of the biggest challenges in food packaging is the creation of sustainable and eco-friendly packaging materials to shield foods from ultraviolet (UV) photochemical damage and to preserve the distinctive physical, chemical, and biological characteristics of foods throughout the supply chain. Accordingly, this study focuses on enhancing the UV shielding properties and biological activity of carboxylmethyl cellulose sodium (CMC) through modifications using zinc oxide (ZnO), copper oxide (CuO), and graphene oxide (GO) using the solution casting technique. The hybrid nanocomposites were characterized by fourier-transform infrared (FTIR) spectrophotometer, ultraviolet-visible (UV-Vis) spectrophotometer, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and x-ray diffraction (XRD). Significant interactions between CMC and the metal oxide/GO nanocomposites were revealed by FTIR analysis, which reflects the formation of hydrogen bonding between CMC and the nanocomposites. XRD confirmed the functionalization of CMC with ZnO/GO and CuO/GO nanocomposites. Additionally, the CMC film showed a decrease in the optical bandgap from 5.53 to 3.43eV with improved UV shielding capacity. Moreover, the composite films had excellent refractive index and optical conductivity values of 1.97 and 1.56 × 1010Ωcm- 1, respectively. SEM and EDX analysis confirmed the formation of ZnO/GO and CuO/GO within the CMC matrix. Thus, dedicates that the CMC nanocomposites have promising applications in packaging materials. These results were confirmed by the quantum mechanical calculations utilizing density functional theory (DFT). Total dipole moment (TDM), frontier molecular orbitals (FMOs), chemical reactivity descriptors, and molecular electrostatic potential (MESP) maps were all studied using the B3LYP/LanL2DZ model. The TDM and FMO investigations revealed that the CMC/CuO/GO model has the highest TDM (84.031 Debye) and the smallest band gap energy (0.118eV). Moreover, CMC's reactivity increased after CuO/GO nanocomposites integration, as demonstrated by MESP mapping. Finally, the antibacterial activity of pure CMC, CMC/ZnO/GO, and CMC/CuO/GO nanocomposite films was evaluated against Staphylococcus aureus and Escherichia coli. The zones of inhibition data showed that both CMC/ZnO/GO and CMC/CuO/GO exhibited higher antibacterial activity than CMC alone, particularly against S. aureus. The inhibition zones for CMC/ZnO/GO and CMC/CuO/GO against S. aureus were 16mm and 14mm, respectively, suggesting enhanced susceptibility of S. aureus compared to E. coli. These results highlight the significant potential of ZnO and CuO NPs in improving the antimicrobial efficacy of CMC nanocomposites.

Biosynthesis and Characterisation of Silver Nanoparticles using Leaf Extract of <i>Gardenia resinifera</i> and its Antioxidant and Photocatalytic Degradation Activity

Background: Green synthesis of nanoparticles and their bioactive applications have always been significant in the present scenario. Nanomedicine is a promising alternative approach for the development of sensitive and selective drugs for fast-progressing ailments like inflammation and cancer. Aim: The purpose of this study is to synthesise and characterise silver nanoparticles from the leaf extract of Gardenia resinifera and to test its application as an antioxidant agent. Methods: The green synthesised silver nanoparticle was authenticated and validated by Ultraviolet-Visible spectrophotometer (UV-Vis Spec), Fourier-transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopic (SEM) analyses. Results: In UV-Vis spectrophotometric analysis a change in colour of the mixture of plant extract and AgNPs (Silver nanoparticles) from green to yellowish-brown confirms the production of AgNPs. The presence of 12 peaks in FTIR spectra represents the respective bands and stretches of the bonds. SEM image shows the spherical shape of the AgNPs and an average size ranging from 70 nm to 100 nm. The most frequently used methods for determining antioxidant activity are the ABTS (2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays and they are based on the reaction of coloured radicle measured by spectrophotometric methods. The antioxidant capacity of synthesised AgNPs was evaluated by these assays and compared with leaf extract and a standard. These findings strongly suggest that AgNPs may play a therapeutic role in oxidative stress-associated disorders. A 100% photocatalytic degradation of methylene blue a synthetic dye resulted in the presence of synthesised AgNPS. Based on the result it is evident that a gradual decrease in absorption peak was observed by an increase in reaction time which indicates the degradation of methylene blue dye. Conclusion: The present study explains the possibility of silver nanoparticles synthesised using G. resinifera leaf extract as an antioxidant agent due to its efficiency in radical scavenging.

Application of green synthetic iron oxide nanocatalyst in biohydrogen production from domestic wastewater.

Hydrogen (H2) is considered to be an energy carrier with high yields in future. Using green nanoparticles as the catalyst to produce H2 from organic wastes is an environmentally friendly and cost-effective approach. This study specifically addresses H2 production biologically from domestic wastewater using dark fermentation process with green nanoparticles in anaerobic condition. In this investigation, acid, alkaline, and heat pre-treated wastewater were utilized as the feedstock and identified that the alkaline pre-treated wastewater was an efficient feedstock for H2 production. The reaction conditions such as pH, time, and nanocatalyst dosage were optimized for the enhancement of H2 production. In addition, the green iron oxide nanoparticles (Fe3O4-NPs) were prepared by sustainable way using Murraya koenigii (curry leaves) with FeSO4 and characterized it using Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectrophotometer (UV-vis), power X-ray diffraction (pXRD), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX), further tested for their 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging performance via in vitro antioxidant activities. This study demonstrates that a maximum production of bio-H2 was obtained (72.8mL/L) with 20mg of nanocatalyst load at alkaline condition (pH 9). The correlation coefficient value was highly significant for biohydrogen production with increasing pH (r = 0.9026) and catalyst dosage (r = 0.9962). The characterization studies confirmed the existence of iron oxide nanoparticles in the green synthesized nanoparticles. The in vitro antioxidant assay showed that Fe3O4-NPs effectively reduces the DPPH radical by significantly releasing H-atoms, thereby confirming that the plant extract functions as reducing/oxidizing agents. The high yield under the dark fermentation method has clearly been attributed to the enhancement in bio-H2 production by using the green Fe3O4-NPs based on M. koenigii.

Preparation and Characterisations of Acrylic Epoxy/Polyethylene Glycol/Graphene Oxide Nanocomposites for Antibacterial Coating Applications

This study addresses the urgent need for antibacterial coatings amid escalating concerns about pathogen contamination on various surfaces, particularly in healthcare settings and public spaces where infection control is critical. The development of durable and effective antibacterial coatings could significantly reduce harmful bacteria transmission and improve overall hygiene standards. Graphene oxide (GO) had exceptional antibacterial properties against a wide spectrum of bacteria. Here, the researchers explored the composite of GO with acrylic epoxy (AE) through the use of polyethylene glycol (PEG) to become AE/PEG/GO tertiary nanocomposites in enhancing GO’s antibacterial efficacy. The objectives of this study were to prepare and characterise AE/PEG/GO nanocomposites and then investigate their antibacterial abilities against escherichia coli (E. coli) and staphylococcus aureus (S. aureus) bacteria. The GO was prepared using the modified Hummers method, which was mechanically stirred with AE and PEG to produce the AE/PEG/GO nanocomposites. This was followed by characterisations of the nanocomposites via ultraviolet-visible (UV-Vis) spectrophotometer, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometer and scanning electron microscope (SEM). The nanocomposites were then tested against E. coli and S. aureus bacteria by measuring the diameter of the inhibition zone (DIZ). The results showed that the absorption peak of GO was obtained at a wavelength of 236 nm. The diffraction pattern of the AE/PEG/GO nanocomposites showed amorphous structure with a small and wide peak at 2 around 23°. The IR spectrum of the AE/PEG/GO nanocomposites indicated the presence of –OH, –CH3, –CH2, C=O, C–H, C–O and C=C functional groups. The surface morphology showed well-distributed nanocomposite coating onto glass slides with some micro islands. The nanocomposites exhibited promising antibacterial performance revealing higher efficacy against S. aureus compared to E. coli. This was shown by the performance of AE/PEG/GO coating in inhibiting S. aureus bacteria with 1.55 mm larger DIZ compared to the positive control. However, the AE/PEG/GO coating exhibited smaller DIZ than the positive control with a difference of 3.68 mm in inhibiting E. coli bacteria. This study unveiled a simple and straightforward approach in producing nanocomposites for antibacterial coatings shedding light on their potential applications in safeguarding surfaces against bacterial contamination.

Comparative evaluation of apical microleakage of mineral trioxide aggregate, Biodentine, and Bio-C Repair as root-end filling materials using dye extraction method: An in vitro study

Context: Root-end filling materials enhance the apical sealing ability of the root canal to avoid leakage of irritants and to prevent the reentering of microorganisms. Aim: The objective of the present study was to compare and evaluate apical microleakage in retrograde filling materials with mineral trioxide aggregate (MTA), Biodentine, and Bio-C Repair using an ultraviolet (UV)–visible spectrophotometer. Materials and Methods: Fifty maxillary incisors were selected and decoronated. Instrumentation was done with ProTaper rotary files and obturated with AH Plus sealer and ProTaper gutta-percha cone using lateral condensation technique. The apical part of each root was resected at 90° to the long axis of the root for 3 mm, and retrograde cavity preparation was done up to 3 mm using an ultrasonic retro tip. After conditioning the root end with 17% ethylenediaminetetraacetic acid, the teeth were divided into four groups. Group 1 = Positive Control (n = 5), Group 2 was filled with MTA (n = 15), Group 3 was filled with Biodentine (n = 15), and Group 4 was filled with Bio-C Repair (n = 15). All samples were incubated in 5 mL of 2% methylene blue dye for 72 h after which teeth were immersed in 65% nitric acid for 72 h. The solutions were then filtered using fine grit filter paper and centrifuged at 3500 rpm for 5 min. The solution thus collected was used to determine absorbency in UV–visible spectrophotometer at 550 nm. Statistical Analysis: The data were analyzed using one-way analysis of variance and Tukey post hoc tests. P <0.05 was considered significant for all analyses. Results: The results showed that Biodentine had the least dye absorbance, which means less microleakage, and there was no significant difference between MTA and Bio-C Repair. Conclusion: Biodentine showed superior sealing ability as a retrograde filling material compared to Bio-C Repair and MTA.

Migration and catalytic viscosity reduction of biochar-based catalyst fluid in heavy oil reservoir pores

The method for reducing heavy oil viscosity through catalysts has remained experimental. Catalyst aggregation in reservoirs is a challenging issue. This study prepares catalyst fluids with both hydrophilic and oleophilic properties and uses dispersants to inhibit aggregation. Stability is assessed using direct observation and an ultraviolet-visible spectrophotometer, with results showing that a dispersant concentration of 0.05 wt. % stabilizes catalyst fluids. Micromodel experiments are conducted to investigate the catalytic performance and dispersion characteristics of catalyst fluids under various conditions. A post-processing method based on the hue, saturation, and value color space for image recognition and error calculation is proposed to analyze the migration and sweeping effects of catalyst fluids. This method involves identifying images captured by a digital camera, calculating area ratios, and determining recognition errors. The results show that catalyst fluids exhibit the best viscosity reduction ratio (80.0%) and the largest dispersion area ratio (55.7%) when the catalyst concentration is 4 wt. %, the injection velocity is 0.01 ml/min, the reaction temperature is 200 °C, and the reaction time is 24 h. With the increase in injection velocity, the viscosity reduction effect becomes worse. The viscosity reduction effect is improved with the increase in reaction temperature. With the growth of reaction time, the viscosity reduction effect increases and then becomes gentle. The combined mechanism of catalytic viscosity reduction and sweeping effects of catalyst fluids in porous media is proposed. This study provides a theoretical foundation for the large-scale development of heavy oil catalytic viscosity reduction.

Evaluation of the Transverse Strength and UV Spectrophotometric Analysis of the Residual Monomer Content of Autoclave Polymerized Conventional and High-Impact Heat-Cure Denture Base Resins—An In-Vitro Study

ABSTRACT Background and Objective: Inspite of advancements in material properties of heat cure acrylic resin, fracture of denture base and allergic reactions due to release of residual monomer is encountered frequently. To improve strength and to reduce residual monomer, different polymerization methods need to be investigated. The objective is to evaluate and compare transverse strength and residual monomer content of two different heat cured denture base resins polymerized by conventional water bath and by autoclave. Materials and Methods: Samples were prepared with Acralyn-H conventional heat cure resin and Acralyn-H super hi-impact resin using metal dies. Samples undergoing water bath polymerization were polymerized in water bath at 74°C for 2 hours followed by 100°C for 1 hour and samples undergoing autoclave polymerization were cured in an autoclave at 121°C and 210 kPa for 30 minutes as holding temperature. Transverse strength specimens were processed and then tested for transverse strength in a Universal testing machine. Specimens for residual monomer content estimation were weighed and each specimen’s residual monomer was extracted in methanol using Soxhlet extractor and then read at 230nm in Ultraviolet-Visible spectrophotometer. Concentrations of residual monomer were evaluated and weight fractions were calculated. Results: The results of this study showed a statistically significant difference in transverse strength of Acralyn-H conventional heat cure resin polymerized by autoclave, whereas all other groups showed a non-significant result. Conclusion: Autoclave can be used as an alternative polymerization technique as it has shown similar results when compared with water bath polymerization and the time required for polymerization was also reduced.

Assessment of Heavy Metal Contamination and Related Risks in well water Sources from Angwa Ashanu Gwagwalada

Consumption of water with heavy metals can accumulate in the body and heighten the likelihood of cancer and other health risk diseases. This study assessed four specific heavy metals, namely lead, cadmium, mercury, and arsenic, in well water samples collected from AngwaAshanuGwagwalada. The analysis was carried out using an atomic absorption spectrophotometer (AAS) and ultraviolet-visible spectrophotometer (UVS) adhering to standardized protocols. The results show that the heavy metals present in AngwaAshanuGwagwaladawell water is as followed: for lead (0.002 mg/L), cadmium (0.020 mg/L), and mercury (0.000 mg/L), and the results were compares with the WHO standards, it was observed that lead and arsenic were above the maximum permissible limit which signifies a potential health risk if used without appropriate treatment. The high level of arsenic 0.059 mg/L may likely be linked to human activities in the area. However, according to regulatory standards, the well water examination revealed that the quantities of mercury, and cadmium were all within permissible ranges

The potential of rice husk waste to synthesise zinc oxide nanoparticles and assessment to the antibacterial activities

n the past decade, open-air burning of rice husks has negatively impacted the environment and human health, particularly in developing and underdeveloped nations. Consequently, the present study established a sustainable and environmentally friendly method of manufacturing zinc oxide nanoparticles (ZnO NPs) from Oryza sativa rice husks using different concentrations of the precursor. The ZnO NPs obtained were analysed with an ultraviolet-visible (UV-Vis) spectrophotometer, which revealed a characteristic ZnO NPs band at 410 nm. Based on Debye-Scherrer’s equation, the ZnO NPs crystallites had a mean size of 20 nm. The Fourier-transform infrared (FTIR) spectra of the ZnO NPs were determined within the 400 to 4000 cm−1 range. The peak at 487 cm−1 indicated that a Zn-O bond was formed. A developed material further evaluated the antibacterial effectiveness of ZnO NPs against four harmful bacteria, demonstrating a moderate level of effectiveness. The findings indicated that all the tested bacteria exhibited heightened susceptibility to ZnO NPs at a higher concentration of 250 μg/mL.

Investigation of Wettability, Thermal Stability, and Solar Behavior of Composite Films Based on Thermoplastic Polyurethane and Barium Titanate Nanoparticles.

Herein, composite films were produced by incorporating different amounts (1, 3, 5, and 7%) of barium titanate nanoparticles into the thermoplastic polyurethane matrix using a solution casting method. This study examined the impact of the presence and concentration of a barium titanate additive on morphologic properties, mechanical performance, thermal stability, solar behavior, and wettability of produced film samples. The films were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, scanning electron microscope, ultraviolet-visible near-infrared spectrophotometer, water contact angle, and tensile strength measurements. In the present study, the mass loss of samples containing 7% barium titanate was 24% lower than that of the pure polyurethane reference. The increase of barium titanate rate added to polyurethane enhanced the solar reflectance property of the films, including the near-infrared region. As a prominent result, the transmittance value decreased significantly compared to the reference in the ultraviolet region, and it dropped to 3% for the highest additive concentration. The contact angle values of polyurethane films increased by 11-40% depending on the barium titanate addition ratio. The nano additive also positively affected the mechanical performance of the reference polyurethane film by slightly increasing the tensile strength values.

Utilizing DNA Logic Device for Precise Detection of Circulating Tumor Cells via High Catalytic Activity Au Nanoparticle Anchoring.

As medical advancements turn most cancers into manageable chronic diseases, new challenges arise in cancer recurrence monitoring. Detecting circulating tumor cells (CTCs) is crucial for monitoring cancer recurrence, but the current methods are cumbersome and costly. This study developed a new CTC detection system combining DNA aptamer recognition, hybridization chain reaction (HCR) technology, and DNA logic devices, enabling the one-step recognition of CTCs by identifying multiple membrane proteins. After catalytically active Au nanoparticles were attached through reduction synthesis in situ onto the DNA hybridization strands of the CTCs surface, a 3,3',5,5'-tetramethylbenzidine (TMB) colorimetric reaction was used to detect CTCs concentration via peroxidase-like catalysis. With this CTCs detection reporting system, we achieved an LOD of 4 cells/mL using an ultraviolet-visible (UV-vis) spectrophotometer. At certain concentrations, CTCs could even be detected visually without the need for an instrument. The development of this CTCs detection reporting system provided a convenient, reliable, and cost-effective detection strategy for widespread CTCs-based cancer recurrence monitoring.

Extraction and characteristic properties analyses of sodium alginate derived from the Sargassum oligocystum brown seaweed alga of the Bay of Bengal

Extraction and characteristic properties analyses of sodium alginate derived from the Sargassum oligocystum brown seaweed alga of the Bay of Bengal

Influence of Ta2O5 nanoparticles on the polyvinyl alcohol films’ structure and optical parameters for UV shielding applications

Influence of Ta2O5 nanoparticles on the polyvinyl alcohol films’ structure and optical parameters for UV shielding applications

Measurement of Fluoride Ion Release From Restorative Material Using an Ion-Selective Electrode and Ultraviolet-Visible Light Spectrophotometer.

Importance of fluoride in dental restorative materials for preventing secondary caries. Several commercially available tooth-colored dental restorative materials, such as glass ionomer cement, resin composites, and compomers were used for this study. To evaluate the amount of fluoride release from tooth-colored restorative materials [Conventional Glass Ionomer Cement (GC Fuji II)], Resin-modified Glass Ionomer Cement (ACTIVA BioACTIVE-RESTORATIVE), and Giomer (BEAUTIFIL II LS)] using ion-selective electrode (ISE) and spectrophotometer using zirconyl alizarin red dye method. A total of 90 extracted premolars were divided into two control groups and four experimental groups. Group I: GC Fuji II/ISE; Group II: BEAUTIFIL II LS/ISE; Group III: ACTIVA BioACTIVE-RESTORATIVE/ISE; Group IV: GC Fuji II/Spectrophotometer; Group V: BEAUTIFIL II LS/Spectrophotometer; and Group VI: ACTIVA BioACTIVE-RESTORATIVE/Spectrophotometer. The amount of fluoride released was analyzed using an ion-selective elective method and spectrophotometer. The results were analyzed using a one-way analysis of variance and Scheffe post hoc tests (P ≤ 0.05). Groups I and IV exhibited the highest fluoride release (1.42 and 1.12 ppm), which was statistically significant (P < 0.05) compared with Groups II and V, which showed the least using both methods. The fluoride release pattern of ACTIVA BioACTIVE (Groups III and VI) restorative was significantly lower than that of glass ionomers and showed no significant difference from the giomers groups (Groups II and IV). Conventional glass ionomer cement (GIC) showed the highest fluoride release followed by enhanced resin-modified GIC and giomer irrespective of the methods used. Fluoride ion concentration values obtained from the ISE method, and spectrophotometer method were comparable. Alizarin red dye can be used as an alternative to sulfanilic acid azochromotrop dye for the estimation of the release of fluoride ions from dental materials, which is known to be sensitive and much more economical compared with the latter.