Exploring the anticancer and antibacterial potential of naphthoquinone derivatives: a comprehensive computational investigation

This study investigates the potential of 2-(4-butylbenzyl)-3-hydroxynaphthalene-1,4-dione (11) and its 12 derivatives as anticancer and biofilm formation inhibitors for methicillin-resistant staphylococcus aureus using in silico methods. The study employed various computational methods, including molecular dynamics simulation molecular docking, density functional theory, and global chemical descriptors, to evaluate the interactions between the compounds and the target proteins. The docking results revealed that compounds 9, 11, 13, and ofloxacin exhibited binding affinities of −7.6, −7.9, −7.5, and −7.8 kcal mol−1, respectively, against peptide methionine sulfoxide reductase msrA/msrB (PDB: 3E0M). Ligand (11) showed better inhibition for methicillin-resistant staphylococcus aureus msrA/msrB enzyme. The complex of the 3E0M-ligand 11 remained highly stable across all tested temperatures (300, 305, 310, and 320 K). Principal Component Analysis (PCA) was employed to evaluate the behavior of the complex at various temperatures (300, 305, 310, and 320 K), demonstrating a total variance of 85%. Convergence was confirmed by the eigenvector’s cosine content value of 0.43, consistently displaying low RMSD values, with the minimum observed at 310 K. Furthermore, ligand 11 emerges as the most promising candidate among the compounds examined, showcasing notable potential when considering a combination of in vitro, in vivo, and now in silico data. While the naphthoquinone derivative (11) remains the primary candidate based on comprehensive in silico studies, further analysis using Frontier molecular orbital (FMO) suggests while the Egap value of compound 11 (2.980 eV) and compound 13 (2.975 eV) is lower than ofloxacin (4.369 eV), indicating their potential, so it can be a statement that compound 13 can also be investigated in further research

Effect of surface patterning using femtosecond laser on micromechanical and structural properties of micromechanical sensors

A femtosecond laser can be used to fabricate microstructures on a silicon microcantilever surface with high precession and minimal sidewall defects. The aim of this study is to investigate the effect of the creation of microgrooves and sub-microgrooves on the resonance frequency, quality factor, and spring constant of a silicon microcantilever. A single pass of a femtosecond laser with a wavelength of 1026 nm was used to fabricate microgrooves on the microcantilever surface. Different numbers of microgrooves were fabricated on each microcantilever using the femtosecond laser micromachining technique. The separation distance between the center of the two microgrooves was 7 μ m. The microstructure of the fabricated microgrooves was investigated through field emission electron microscopy. The resonance frequency increased with the number of microgrooves, but the quality factor of the patterned microcantilever was higher than that of the unpatterned microcantilever. The spring constant increased with the number of microgrooves, increasing from 18.96 to 38.04 mN/m for microcantilevers with 1 and 7 microgrooves, respectively

Extracting mechanical and microstructural properties of Cu–Zr thin film alloys by MEMS, AFM and ellipsometer

The quantification of the atomic concentration ratios of thin-film metallic alloys having low atomic ordering is challenging, particularly if they are grown on similar metals and possess different surface chemistries. Micromechanical and optical methods have been used to correlate the elemental ratios with the mechanical and optical properties of the films. The room-temperature growth of Cu–Zn thin-film alloys with varying elemental ratios on cosputtered Si substrates was performed to obtain an amorphous film structure. X-ray diffraction patterns confirmed that the grown films exhibited a very short range ordering, suggesting an amorphous structure. The mechanical properties of the films evaluated using microelectromechanical system (MEMS) indicated that the alloy films with moderate Zr concentrations had lower surface stress compared to those with low and high Zr concentrations. Furthermore, spectroscopic ellipsometry was employed to qualitatively assess the relaxation times of free carriers. The results demonstrated a strong correlation between the relaxation times and surface roughness measurements, showing that the microstructure and resistivity characteristics of the alloys align with the Nordheim semiempirical model. The extinction coefficient of the binary alloy film linearly depends on the metallic bulk concentration ratio in a specific metallic ratio range, paving the way for realizing qualitative elemental percentage assessment in the field of metrology

Quartz tuning fork-based biosensor for the direct detection of human cytomegalovirus

Human cytomegalovirus (HCMV) possess great threat to immunocompromised patients and pregnant women since It can cause disability if left untreated. Especially for unborn babies, if the virus was not detected at early stages, it can cause disabilities as the baby develops. Furthermore, the virus can be asymptomatic, hence, low-cost and rapid detection techniques are desirable. Currently available detection techniques of the virus are labor intensive and demand experienced technicians. For these reasons, new detection techniques are needed to overcome the current challenges associated with conventional techniques. In this work, quartz tuning fork (QTF)-based biosensor was developed for the detection of UL83-antigen of HCMV for the first time. Firstly, QTF coated with gold was functionalized with cysteamine and glutaraldehyde for UL83-antibody immobilization at the QTF surface. Then, the biosensor was tested against a variety of UL83-antigen concentrations. As the UL83-antigen concentration increased, the measured resonance frequency decreased due to increased mass loading at the QTF surface. The sensitivity of the biosensor is 15.91 Hz/ln(ng/mL). Whereas the limit of detection is 0.36 ng/mL. The biosensor showed comparable biosensing performances to those available in the literature. Furthermore, the biosensor demonstrated its selectivity towards UL83-antigen when tested against samples containing a mixture of biomarkers. The reported work demonstrates a platform for the direct and low-cost mass screening of diseases

The Effect of Counterions on the Detection of Cu²⁺ Ions in Aqueous Solutions Using Quartz Tuning Fork (QTF) Sensors Modified with L-Cysteine Self-Assembled Monolayers: Experimental and Quantum Chemical DFT Study

In this study, a sensing device employing a gold-coated quartz tuning fork (QTF) modified with a self-assembled monolayer (SAM) of L-cysteine was evaluated for the sensitive detection of Cu2+ ions in aqueous solutions. Three copper (II) salts, CuSO4, CuCl2, and Cu(NO3)2, at four different concentrations (10−12, 10−10, 10−8, and 10−6 M) in small (100 μL) water sample amounts were each used as analytes to investigate the influence of their counterions in the detection of the Cu2+ ions. It was found that, among the counterions, the sulfate anion had the largest effect upon the detection of Cu2+ in water, in the following order: SO42− > Cl− > NO3−. The lower limit of detection of the Cu2+ ions detected was in the 10−12 M range. The frequency shifts measured with the QTFs relative to deionized water were inversely proportional to the concentration/mass of the analytes. Density functional theory calculations were conducted to understand the effect of the counterions on the respective electronic interaction energies for the apparent host–guest binding of the analytes with L-cysteine and with gold surface-bound L-cysteine molecules. Gas phase (both with and uncorrected BSSE) and solution phase interaction energies (ΔIE) calculated at the B3LYP/LANL2DZ and ωB97XD levels of theory showed that the stability for the complexes were in the following order: [L-cysteine]⊃[CuSO4] > [L-cysteine]⊃[CuCl2] > [L-cysteine]⊃[Cu(NO3)2], which supports our experimental findings, as they were in the same order as the experimentally observed order for the copper salts tested: CuSO4 > CuCl2 > Cu(NO3)2

The Effect of Counterions on the Detection of Cu2+ Ions in Aqueous Solutions Using Quartz Tuning Fork (QTF) Sensors Modified with L-Cysteine Self-Assembled Monolayers: Experimental and Quantum Chemical DFT Study

In this study, a sensing device employing a gold-coated quartz tuning fork (QTF) modified with a self-assembled monolayer (SAM) of L-cysteine was evaluated for the sensitive detection of Cu2+ ions in aqueous solutions. Three copper (II) salts, CuSO4, CuCl2, and Cu(NO3)2, at four different concentrations (10−12, 10−10, 10−8, and 10−6 M) in small (100 μL) water sample amounts were each used as analytes to investigate the influence of their counterions in the detection of the Cu2+ ions. It was found that, among the counterions, the sulfate anion had the largest effect upon the detection of Cu2+ in water, in the following order: SO42− > Cl− > NO3−. The lower limit of detection of the Cu2+ ions detected was in the 10−12 M range. The frequency shifts measured with the QTFs relative to deionized water were inversely proportional to the concentration/mass of the analytes. Density functional theory calculations were conducted to understand the effect of the counterions on the respective electronic interaction energies for the apparent host–guest binding of the analytes with L-cysteine and with gold surface-bound L-cysteine molecules. Gas phase (both with and uncorrected BSSE) and solution phase interaction energies (ΔIE) calculated at the B3LYP/LANL2DZ and ωB97XD levels of theory showed that the stability for the complexes were in the following order: [L-cysteine]⊃[CuSO4] > [L-cysteine]⊃[CuCl2] > [L-cysteine]⊃[Cu(NO3)2], which supports our experimental findings, as they were in the same order as the experimentally observed order for the copper salts tested: CuSO4 > CuCl2 > Cu(NO3)2

Detection of Volatile Alcohol Vapors Using PMMA-Coated Micromechanical Sensors: Experimental and Quantum Chemical DFT Analysis

Micromechanical sensors, in which the sensor response is created as a result of molecular interactions on the sensors’ surfaces, have been employed as a powerful technique for rapid and sensitive detection of low concentrations of chemical and biological materials. In the study reported herein, poly(methyl methacrylate) (PMMA)-coated microcantilever (MCL) sensors were used to detect the vapors of volatile alcohols (methanol, ethanol, and isopropanol) at three different concentrations. A vapor generator was used to generate and flow the alcohol vapor onto the PMMA coated MCL surface in a closed system chamber. The vapor adsorption onto the MCL surface results in a rapid and measurable deflection of the MCL. No significant deflections of the uncoated MCL occurred when the different vapors were passed through into the microcantilever chamber. Linear concentration–deflection responses were observed, with the highest sensitivity shown with methanol, followed by ethanol and then isopropanol. Density functional theory (DFT) quantum chemical calculations were conducted to estimate the electronic interaction energies (ΔIE) between the alcohol molecules and MMA and two different model tetrameric segments of PMMA. The computed ΔIEs were in the same order as the experimentally observed order: methanol > ethanol > isopropanol

Detection of Volatile Alcohol Vapors Using PMMA-Coated Micromechanical Sensors: Experimental and Quantum Chemical DFT Analysis

Micromechanical sensors, in which the sensor response is created as a result of molecular interactions on the sensors’ surfaces, have been employed as a powerful technique for rapid and sensitive detection of low concentrations of chemical and biological materials. In the study reported herein, poly(methyl methacrylate) (PMMA)-coated microcantilever (MCL) sensors were used to detect the vapors of volatile alcohols (methanol, ethanol, and isopropanol) at three different concentrations. A vapor generator was used to generate and flow the alcohol vapor onto the PMMA coated MCL surface in a closed system chamber. The vapor adsorption onto the MCL surface results in a rapid and measurable deflection of the MCL. No significant deflections of the uncoated MCL occurred when the different vapors were passed through into the microcantilever chamber. Linear concentration–deflection responses were observed, with the highest sensitivity shown with methanol, followed by ethanol and then isopropanol. Density functional theory (DFT) quantum chemical calculations were conducted to estimate the electronic interaction energies (ΔIE) between the alcohol molecules and MMA and two different model tetrameric segments of PMMA. The computed ΔIEs were in the same order as the experimentally observed order: methanol > ethanol > isopropanol