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We introduce silver-copper nanoparticles incorporated into polyaniline (PANI) nanotubes using a straightforward and efficient reduction process. In this regard, PANI nanotubes with ...amine groups were fabricated through oxidation polymerization, followed by the attachment of Ag and Cu precursors to enable the synthesis of Ag-Cu bimetallic nanoparticles (NPs) on the pre-formed PANI nanotubes with the use of hydrazine as a reducing agent. The structural characterization of the synthesized NPs was investigated by UV–Vis spectrophotometer (UV–Vis), Dark-field emission, (EDX), X-ray diffraction (XRD) and field emission (FESEM), while the electrochemical properties were estimated by (CV) and differential pulse voltammetry (DPV). The findings indicated that the Ag-Cu NPs were present in the nanoscale range, well-dispersed, and attached to the surface of PANI nanotubes. Electrochemical investigations revealed that the Ag-Cu@PANI nanotube electrode demonstrated efficient electrooxidation of dopamine and hydroquinone without any interfering reactions, suggesting its potential use as an electrochemical biosensor for simultaneous detection of dopamine and hydroquinone. The proposed NPs-based biosensor was connected to concurrently identify dopamine and hydroquinone, illustrating moo distinguish Confinements of 0.46 µM for dopamine and 0.23 mM for hydroquinone, separately. Additionally, the manufactured sensor identified on a wide direct run the dopamine (5–25 µM), and hydroquinone (0.5–2.5 mM). Alongside these promising comes about, the Ag-Cu@PANI nanotube actualized great solidness and reproducibility, making it a favorable stage for electrochemical biosensing of dopamine and hydroquinone.
In the mammalian brain, dopamine is a critical neuromodulator whose actions underlie learning, decision-making, and behavioral control. Degeneration of dopamine neurons causes Parkinson’s disease, ...whereas dysregulation of dopamine signaling is believed to contribute to psychiatric conditions such as schizophrenia, addiction, and depression. Experiments in animal models suggest the hypothesis that dopamine release in human striatum encodes reward prediction errors (RPEs) (the difference between actual and expected outcomes) during ongoing decision-making. Blood oxygen level-dependent (BOLD) imaging experiments in humans support the idea that RPEs are tracked in the striatum; however, BOLD measurements cannot be used to infer the action of any one specific neurotransmitter. We monitored dopamine levels with subsecond temporal resolution in humans (n = 17) with Parkinson’s disease while they executed a sequential decision-making task. Participants placed bets and experienced monetary gains or losses. Dopamine fluctuations in the striatum fail to encode RPEs, as anticipated by a large body of work in model organisms. Instead, subsecond dopamine fluctuations encode an integration of RPEs with counterfactual prediction errors, the latter defined by how much better or worse the experienced outcome could have been. How dopamine fluctuations combine the actual and counterfactual is unknown. One possibility is that this process is the normal behavior of reward processing dopamine neurons, which previously had not been tested by experiments in animal models. Alternatively, this superposition of error terms may result from an additional yet-to-be-identified subclass of dopamine neurons.
It is still challenging to clarify the intrinsic relationship between the photostability and molecular structures of rhodamine dyes. Herein, we investigated the photostability of three rhodamine dyes ...RhB, Rh101, and Rh101-ME in water and 20%EtOH–H2O solutions under 525 nm LED light irradiation. The photostability of RhB is much higher than that of Rh 101 and Rh101-ME, indicating that forming rigid ring between the N-linked alkyl and xanthene can significantly decrease the photostability of rhodamine dyes, while the esterification of carboxyl on benzene ring can improve their photostability. The EPR analyses and radical trapping experiments proved that 1O2 is the most important reactive oxygen species responsible for dye degradation, and the Rh101 and Rh101-ME have higher 1O2 and •OH production rates than RhB. The cyclic voltammetry tests showed that forming rigid ring between the N-linked alkyls and xanthene can decrease the oxidation potential of RhB and consequently lower down its photostability. The theoretical calculations disclosed that the higher HOMO energy levels in ground states and lower singlet–triplet energy gaps of Rh101 and Rh101-ME are the main factor that results in their lower photostability when compared with RhB.
Forming rigid ring between the N-linked alkyl and xanthene of rhodamine dyes significantly decreases the photostability of rhodamine dyes, which is related to the structure distortion on the twisted intramolecular charge transfer (TICT). In addition, the esterification of –COOH on benzene ring improves the photostability to some extent. Display omitted
•The influence of rhodamine molecular structures on their photostability was investigated.•Forming rigid ring between N-linked alkyl and xanthene reduces the photostability of rhodamine dye.•Esterification of carboxyl acid on benzene ring can improve the photostability of rhodamine dyes.•1O2 is the most important reactive oxygen species responsible for rhodamine dye degradation.•The calculation reveals that the photostability of dyes is related to their S0 energy levels and T1 energy gaps.
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•Monometallic heteroleptic complexes of Dy(III) with general formula Dy(Hfodo)3L have been synthesized.•The prepared complexes have been investigated by thermal, spectroscopical and ...electrochemical studies.•Electronic and optical band gap has found to be quite similar and in the range of conducting region.•Yellow luminescence is observed corresponding to 4F9/2→6H13/2 transition which demonstrates the utility of complexes in generation of high-efficiency organic light emitting materials.
A series of ternary complexes of dysprosium tris-β-diketonate was prepared by using phenanthroline and its substituted derivatives as neutral ligands. The complex formation or the coordination mode of organic moieties was analysed by elemental, infrared, proton NMR and UV–Visible analyses. The anhydrous nature of prepared complexes was illustrated by using thermogravimetric and infrared studies. The band gap was also measured which is present in the range of conducting zone. The luminescence characteristics were measured in solid and solution. The complex upon excitation under UV light generates emission in the yellow region which indicates proficient energy transference from coordinated moieties to the central Dy(III) ion. The correlated color temperature (CCT) of Dy(III) complexes has been calculated and found to be ∼ 5000 K which belongs to a cold light region. The contribution of 4F9/2 → 6H13/2 transition (75 %) is highest towards total radiative processes and it might be regarded as an acceptable transition for laser amplification. The prepared complexes of Dy(III) could be utilized in fabricating OLEDs and displays due to their band gap value, large thermal stability and high luminous characteristics.
•Binary metal phosphate based on nickel-manganese (Ni-Mn) nanocomposites were synthesized employing facile sonochemical approach.•Electrochemical performance of as synthesized nanomaterials was ...investigated in three electrode cell configuration performing CV, GCD and EIS for supercapacitor application.•Supercapattery device is fabricated comprises of Ni0.75Mn0.25(PO4)2 as positive and activated carbon as negative electrode.•Designed supercapattery device exhibits an outstanding specific energy of 64.2 Whkg−1 with a maximum specific power of 11,896 Wkg−1, along with excellent cyclic stability of 119% after 2000 consecutive charge discharge cycles.•On the bases of Dunn's model the kinetics of charge storage process is determined which evaluates the capacitive and diffusion-controlled contribution in asymmetric supercapacitors.
This study demonstrates a cost-effective, facile and green synthesis of nickel-manganese (Ni-Mn) based binary metallic phosphates through a one-step sono-chemical method followed by calcination at 400 °C. The composites are further modified by changing the aspect ratio of Mn in Ni and utilized for high performance energy storage applications. The structure morphology of synthesized nanomaterials is investigated by performing X-ray diffraction (XRD) analysis. Among all, the composite with a concentration of Ni0.75:Mn0.25(PO4)2 exhibit the outstanding electrochemical performance by indicating high specific capacity (Qs) of 788.4 Cg−1 in three-electrode assembly. At last, the supercapattery is fabricated comprising of active material Ni0.75Mn0.25(PO4)2 as positive and activated carbon as negative electrode, which reveal exceptional results with a high specific energy and specific power of 64.2 Whkg−1 and 11,896 Wkg−1, respectively. This supercapattery device demonstrates excellent cyclic stability of 119% after 2000 continues GCD cycles. Our investigation reveals that the facile synthesis of these nanomaterials along with excellent electrochemical performance makes them valuable for the development of advanced high-performance energy storage devices.
Cyclic voltammetric technique using glassy carbon electrode of cobalt chloride Co(Ⅱ) was studied in blood medium for the effect of ascorbic acid as an electrocatalyst reagent on the oxidation ...reduction current peaks of Co(Ⅱ). It was found that the two oxidation reduction current peaks for Co(Ⅱ) in 0.1M KCl as electrolyte were at 900 and 250 mV respectively. In the study of Co(Ⅱ) in blood medium the result was different, in that the reduction current peak disappeared and the oxidation current peak shifted to a higher potential at 1.4 V. The other study for the effects of different concentrations of ascorbic acid on the anodic current peak of Co(Ⅱ) in blood medium showed an enhancement of the oxidation current peak about three times and the ascorbic acid acted as an electrocatalyst in blood components which caused damage to blood cells.
The present report investigates the various MoO3 morphologies prepared via different approaches such as morphologies are cubic sheet, ribbon, and hexagonal sheet. These prepared nanostructures are ...modified as a MoO3/Ni–F electrode used to detect hydrogen peroxide (H2O2). The influence of the morphology on the microstructural, morphological, electronic state, optical and electrochemical properties of MoO3 nanostructures are systematically studied. The recorded XRD spectra confirmed that the good crystalline nature with the orthorhombic crystal structure. The FESEM analysis shows that preparation approaches strongly influenced the MoO3 morphology. The elemental mapping and XPS analysis confirm the formation of MoO3. The obtained optical band gap values show that the MoO3 morphology-based bandgap values are 3.38, 3.17, and 2.94 eV. The modified MoO3/Ni–F electrode electrochemical impedance spectra show the CP-MoO3 has good conductivity. Moreover, the CP-MoO3/Ni–F electrode has a wide detection window, long-term stability, reproducibility, and a low detection limit is 1.2 μM. Hence, the CP-MoO3/Ni–F electrode electrochemical results suggest that the modified electrode has offered a good matrix for toxic contaminants sensing applications.
•The cubic sheet, ribbon, and hexagonal sheet MoO3 morphologies have prepared via different facile approaches.•The prepared MoO3 nanostructures have formed without disturbing orthorhombic crystal structure.•The modified MoO3/Ni–F electrode shows the has good electrochemical properties.•The CP-MoO3/Ni–F electrode has a wide detection window, long-term stability, reproducibility, and a low detection limit is 1.2 μM.•The electrochemical sensing results suggest that the MoO3/Ni–F electrode is a potential candidate for sensing various pollutants.
To investigate the effect of endogenously released dopamine on the stimulus-induced blood oxygen level–dependent (BOLD) responses, we used rats expressing inhibitory designer receptors exclusively ...activated by designer drugs (DREADDs) in neurons of the ventral tegmental area (VTA) and electrically stimulated the fimbria/fornix. This stimulation activates multiple components of the mesolimbic dopamine system, as demonstrated by the BOLD signal changes during functional magnetic resonance imaging (fMRI) and dopamine release in the nucleus accumbens (NAcc) as detected by
fast-scan cyclic voltammetry. Activation of inhibitory DREADDs by clozapine
-oxide (CNO) significantly reduced stimulus-induced dopamine release and the BOLD response in the NAcc. In contrast, the concurrently induced BOLD response in the medial prefrontal cortex (mPFC) was not significantly reduced after CNO administration, but the hemodynamic response was shifted to the left. Specifically, the Granger causality test showed that the temporal relationship between the BOLD signal changes in the hippocampus and the mPFC, changed. Under control conditions (i.e., in the absence of CNO), the BOLD signal changes in the mPFC and NAcc clearly preceded the BOLD signal changes in the right hippocampus, whereas in the presence of CNO this was only the case for the BOLD signal changes in the NAcc. In the control rats, that is, the rats that received a control virus and thus did not express DREADDs in the VTA, this CNO-mediated effect was not present. Our results indicate that activation of the endogenous dopaminergic system has region-specific effects on the stimulus-induced BOLD responses, so there is no generally applicable fMRI parameter that clearly indicates increased activity of the dopaminergic system.
The impact of 316L stainless steel discolouration on chloride induced pitting corrosion was quantified. Several degrees of discolouration were produces by chemical passivation, simulated rouging or ...anodic polarization. Discolouration was characterized by spectral analysis in the visible and NIR range (400-1000 nm). Pitting corrosion resistance was quantified by pitting potential measurements. The spectra were used to indicate whether pitting or transpassive behaviour would occur using chemometric classification techniques with 88% accuracy. In addition, pitting potentials were predicted combining chemometrics and survival analysis techniques with a 90 mV RMS error in cross-validation. XPS analysis linked pitting resistance with the Cr/Fe balance.
•316L surface discolouration can be quantified by Vis-NIR spectral measurements.•The occurrence of pitting was predicted by application of chemometric classification.•The pitting potential was predicted by application of chemometric survival analysis.•Transpassive outcomes are included by combining chemometric and survival regression.
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