- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Biocompatible Palladium Telluride Quantum Dot-Amplified Biosensor for HIV Drug
摘要： Indinavir (IDV) is a potent and well-tolerated protease inhibitor antiretroviral (ARV) drug used as a component of the highly active antiretroviral therapy (HAART) of human immunodeficiency virus (HIV). It undergoes hepatic first-pass metabolism that is catalysed by microsomal cytochrome P450-3A4 enzyme (CYP3A4), which results in pharmacokinetics that may be favourable or adverse. Therapeutic drug monitoring (TDM) of IDV during HIV treatment is therefore critical, in order to prevent the adverse effects of its first-pass metabolism and optimise an individual’s dosage regime. Biosensors are now the preferred diagnostic tools for TDM assessment at point-of-care, due to their high sensitivity and real-time response. An electrochemical biosensor for IDV was prepared by depositing a thin film of CYP3A4 (a thiolate enzyme) and thioglycolic acid-capped palladium telluride quantum dot (TGA-PdTeQD) on a cysteamine-functionalised gold disk electrode (Cyst|Au) using a combination of thiol and carbodiimide covalent bonding chemistries. The electrochemical signatures of the biosensor (CYP3A4|TGA-PdTeQD|Cyst|Au) were determined by cyclic voltammetry (CV) that was performed at a scan rate of 500 mV s?1, and the sensor responses at the characteristic reduction peak potential value of ? 0.26 V were recorded. The sensitivity, linear range (LR) and limit of detection (LOD) values of the indinavir biosensor were 4.45 ± 0.11 μA nM?1 IDV, 0.5–1.0 nM IDV (i.e. 3.6 × 10?4–7.1 × 10?4 mg L?1 IDV) and 4.5 × 10?4 mg L?1 IDV, respectively. The values of the two analytical parameters (LR and LOD) of the biosensor were by up to four orders of magnitude lower than the maximum plasma concentration (Cmax) values of indinavir (0.13–8.6 mg L?1 IDV). The IDV biosensor was successfully used to detect IDV in human serum samples containing dissolved indinavir tablet. This, therefore, indicates the indinavir biosensor’s suitability for TDM applications, using samples obtained within 1–2 h of drug intake at point-of-care, for which very low levels of the drug are expected.
关键词： Human serum,Limit of detection,Indinavir,Palladium telluride quantum dot,Cyclic voltammetry,Electrochemical sensors,Cytochrome P450-3A4
更新于2025-09-16 10:30:52
-
Effect of organic dyes and polypyrrole on the efficiency of dye-sensitized solar cells
摘要： Polypyrrole films were coated on conductive glass by electrochemical deposition (alternative current of direct process). They were then used as the dye-synthesized solar cell counter electron electrodes. Scanning electron microscopy revealed that polypyrrole forms a nanoparticle like structure on the conductive glass. In the present study, two new organic dyes based on aniline and substituted 5-Nitrosalicylaldehyde with aniline were prepared and used and sensitizes in dye-sensitized solar cells. These dyes in solution and on a nano-anatase v2o5 substrate were investigated. Additionally, oxidation potential measurement were also carried out. Finally, dye-sensitized solar cells were fabricated to determine and conversion efficiency of each dye.
关键词： FESEM,Cyclic Voltammetry,FT-IR,Dye-sensitized solar cells,UV Spectroscopy,XRD,Nitrosalicylaldehyde-aniline
更新于2025-09-16 10:30:52
-
Electrochemical performance of indium-tin-oxide-coated lossy-mode resonance optical fiber sensor
摘要： Analysis of liquids performed in multiple domain, e.g., optical and electrochemical (EC), has recently focus significant attention. Our previous works have shown that a simple device based on indium-tin-oxide (ITO) coated optical fiber core may be used for optical monitoring of EC processes. At satisfying optical properties and thickness of ITO a lossy-mode resonance (LMR) effect can be obtained and used for monitoring of optical properties of an analyte in proximity of the ITO surface. However, EC response of the ITO-LMR device to a redox probe has not been achieved for ITO-LMR sensor whereas it is generally observed for commercially available ITO electrodes. The changes in the response to a redox probe are typically used as a sensing parameter when EC label-free sensing is considered, so it is crucial for further development of combined LMR-EC sensing concept. In this work, we focus on enhancing the EC activity of the device by tuning ITO magnetron sputtering deposition parameters. Influence of the deposition pressure on the ITO properties has been the main consideration. Both optical and EC readouts in 0.1 M KCl containing such redox probes as 1 mM of K3[Fe(CN)6] or 1 mM 1,1′-Ferrocenedimethanol were discussed at different scan rate. The performed studies confirm that for optimized ITO properties the ITO-LMR sensor used as the EC electrode may also show excellent EC performance. The observed EC processes are quasi-reversible and diffusion-controlled. Moreover, for the devices, which offer improved EC response, an optical monitoring of the EC process is also possible. According to our best knowledge, fully functional combined optical and EC sensor, where optical effect is resonance-based and other than well-known surface plasmon resonance, is presented for the first time.
关键词： Electrochemical properties,Cyclic voltammetry,Optical properties,Lossy-mode resonance,Optical fiber sensor,Indium tin oxide,Magnetron sputtering
更新于2025-09-16 10:30:52
-
The effect of bis-carboxylic groups of squarylium dyes on the efficiency of dye-sensitized solar cells
摘要： Symmetric squarylium dye (SQIND1) with bi-carboxylic groups has been synthesized and photoelectrochemical properties have been studied in comparison with its non-functionalized analog groups (SQIND2). The experimental results showed that the introduction of anchor carboxylic groups in SQIND1 sensitizer provides a more intimate contact with nanoparticles TiO2 which increases the number of charge carriers transferred from the SQIND1 to the semiconductor. The theoretical calculations and absorbance results show that the electron density of LUMO of SQIND1 is delocalized in the whole chromophore, leading to strong electronic coupling between SQIND1 sensitizer and conducting band of TiO2, resulting in improved dye-sensitized solar cell efficiency compared to SQIND2. Hence, the SQIND1 sensitized exhibit better photovoltaic performance. Although, the absence of any linker groups in the SQIND1, then SQIND1 was perfect efficiently sensitized on porous TiO2 with the long UV–Vis and NIR region up to 800?nm of the spectrum and showed higher remarkable performance of values, such as η of 3.3%, a Jsc of 7.6?mA/cm2, a Voc of 0.59, and FF of 0.73.
关键词： Cyclic voltammetry,Dye-sensitized solar cell,Symmetric squarylium dyes,Photoelectrochemical properties,DFT
更新于2025-09-12 10:27:22
-
Non-enzymatic glucose sensors based on metal structures produced by laser-induced deposition from solution
摘要： The conditions for synthesis of conductive copper and nickel microstructures using laser-induced deposition technique were determined and electrocatalytic activity of these materials towards D-glucose was investigated. It was found out that formation of these conductive electrodes upon laser irradiation occurs only in solutions containing OH- coordinating ligands. Coordination via other functional groups (including carboxyl and amino) does not lead to synthesis of conductive structures. Topology and composition of copper and nickel deposits were observed using scanning electron microscopy and EDX analysis, respectively. The electrochemical properties of the synthesized structures were studied using cyclic voltamperometry and amperometry. The studied materials display linear dependencies of the Faraday current vs. concentration between 2 μM and 1.1 mM for nickel and 0.25 mM and 3 mM for copper.
关键词： Cyclic voltammetry,Nickel,Copper,Laser-induced deposition,Electrochemical sensors
更新于2025-09-12 10:27:22
-
Synthesis, characterization, optical properties, computational characterizations, QTAIM analysis and cyclic voltammetry of new organic dyes for dye-sensitized solar cells
摘要： In recent years, dye-sensitized solar cells (DSSCs) have regarded as potential solar cells for the next generation of photovoltaic technologies. Many organic compounds are explored and used in DSSCs to produce low-cost devices and improve the cell efficiency. In this work, three new heterocyclic purple dyes are synthesized from the reaction of 3-nitropyrazolo[1,5-a]pyridine with various arylacetonitriles for dye-sensitized solar cells (DSSCs), exhibiting high molar extinction coefficients and a broad absorption range led to the good photovoltaic performance of 6.95e7.18%. Physical spectral, analytical data and optical properties are established the structures of the new dyes. The optimized geometries and relevant frontier orbitals of the dyes are obtained by density functional theory (DFT) at the level of B3LYP/6-311 + G(d,p). Electrostatic potential maps and electron density maps of the dyes were also obtained by atoms in molecules (AIM) analysis. Cyclic voltammetry measurement was performed to evaluate the electrochemical properties of the dyes and reversible oxidation waves were observed for them.
关键词： Dye-sensitized solar cells,DFT,3-Nitropyrazolo[1,5-a]pyridine,AIM,Cyclic voltammetry,Purple dyes
更新于2025-09-12 10:27:22
-
Electronic properties of oxidized cyclometalated diiridium complexes: Spin delocalization controlled by the mutual position of the iridium centres
摘要： Four cyclometalated diiridium complexes, with IrCp*Cl (Cp* = η5-C5Me5?) termini bridged by 1,4- and 1,3-bis(p-tolylimino-ethyl)benzene (1, 2), or 1,4- and 1,3-bis(2-pyridyl)benzene (3, 4), were prepared and characterized by nuclear magnetic resonance (NMR) spectroscopy and single-crystal X-ray diffraction (complexes 1, 2 and 4). The two iridium centres in complexes 1 and 3 are thus bound at the central benzene ring in the para-position (trans-Ir2), while those in complexes 2 and 4 in the meta-position (cis-Ir2). Cyclic voltammograms of all four complexes show two consecutive one-electron oxidations. The potential difference between the two anodic steps in 1 and 3 is distinctly larger compared to 2 and 4. The visible - near-infrared (NIR) - short-wave infrared (SWIR) absorption spectra of trans-Ir2 monocations 1+ and 3+ are markedly different from those of cis-Ir2 monocations 2+ and 4+. Notably, strong near-infrared electronic absorption appears only in the spectra of 1+ and 3+ while 2+ and 4+ absorb only weakly in the NIR-SWIR region. Combined DFT and TD-DFT calculations have revealed that (a) 1+ and 3+ (the diiridium-benzene trans-isomers) display HOSO and LUSO evenly delocalized over both molecule halves, and (b) their electronic absorptions in the NIR-SWIR region are attributed to mixed metal-to-ligand and ligand-to-ligand charge transfers (MLCT and LLCT). In contrast, cis-isomers 2+ and 4+ do not feature this stabilizing π-delocalization but a localized mixed-valence state showing a weak IVCT absorption in the SWIR region.
关键词： Mixed-valence State,Cyclometalated Isomers,Cyclic Voltammetry,Diiridium Complex,Spectroelectrochemistry
更新于2025-09-12 10:27:22
-
Electrodeposition of photovoltaic thin films from ionic liquids in ambient atmosphere: Gallium from a chloroaluminate ionic liquid
摘要： At present time, semiconductive thin films used in photovoltaic cells can be successfully electrodeposited using ionic liquids in lab scale. However, scaling-up of this technology is hazardous due to the complexity involved to conduct electrodeposition in inert gas atmosphere. This paper reports on a novel approach for electrodeposition of gallium from a chloroaluminate ionic liquid composed of anhydrous aluminum chloride (AlCl3) and 1-ethyl-3-methylimidazolium chloride (EMIC) in ambient atmosphere, after protection with a non water-absorbable hydrocarbon layer. Cyclic voltammetry (CV) measurements were undertaken to characterize the electrodissolution and electrodeposition behavior of Ga. Potentiostatic electrodeposition experiments were conducted to deposit functional Ga layers on Pt, nickel, and mild steel substrates. SEM/EDX investigations revealed that Ga deposits have inhomogeneous microstructure developed through the progressive nucleation-growth mechanism that has been controlled by diffusion of Ga cations.
关键词： Ionic liquids,Semiconductors,Photovoltaic cells,Cyclic voltammetry,Electrodeposition,Gallium
更新于2025-09-12 10:27:22
-
Electron Transfer Kinetics at Graphene Quantum Dot Assembly Electrodes
摘要： Electrochemical performance of nanostructured carbon electrodes was evaluated using cyclic voltammetry and a simple simulation model. The electrodes were prepared from soluble precursors by anodic electrodeposition of two sizes of graphene quantum dot assemblies (HBC and CQD) onto conductive support. Experimental and simulated voltammograms enabled the extraction of the following electrode parameters: conductivity of the electrodes (a combination of ionic and electronic contributions), density of available electrodes states at different potentials and tunneling rate constant (Marcus-Gerischer model) for interfacial charge transfer to ferrocene/ferrocenium (Fc/Fc+) couple. The parameters indicate that HBC and CQD have significant density of electronic states at potentials more positive than –0.5 V vs Ag/Ag+. Enabled by these large densities, the electron transfer rates at the Fc/Fc+ thermodynamic potential are several orders of magnitude slower than those commonly observed on other carbon electrodes. This study is expected to accelerate the discovery of improved synthetic carbon electrodes by providing fast screening methodology of their electrochemical behavior.
关键词： cyclic voltammetry,kinetics,interface,electrode,electron transfer,graphene quantum dots
更新于2025-09-12 10:27:22
-
Highly Selective and Sensitive Sensing of Toxic Mercury Ions Utilizing Carbon Quantum Dot-Modified Glassy Carbon Electrode
摘要： In this paper, a novel synthesis of 1 nm sized metal-free carbon quantum dots (CQDs) and their electrochemical application vis-à-vis mercury (Hg) sensing have been demonstrated. The characterization of synthesized CQDs was done by FT-IR, HR-TEM, XRD and UV–Vis analysis. Furthermore, the CQD-modified electrode shows an excellent sensing ability toward deleterious Hg ion even when 600-fold of excess of interfering ions such as Cu2+, Pb2+, Cd2+, Na+, K+, Mg2+, Ba2+, Bi2+, Fe2+, Zn2+ and Hg2+ are present. A wide linearity range (0.5–300 nM) and the lowest limit of detection (2.5 nM) are exhibited by the proposed sensor with potential scanning from ? 0.7 to + 0.7 V vs Ag/AgCl at a scan rate of 20 mV. In addition, the CQD-modified electrode displays an outstanding recovery results toward Hg in various real water samples. This study promotes new possibilities of designing various electrochemical sensors based on CQD nanocomposite.
关键词： Differential pulse voltammetry,Mercury,Cyclic voltammetry,Carbon quantum dots,Electrochemical Sensing
更新于2025-09-11 14:15:04