Photolysis Dynamics Laser Chemistry Lab

Porous carbon nanosheets were prepared by the carbonization of paper flower via chemical and physical activation. The structural properties of the as-prepared carbons were characterized using the techniques, such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, N2 sorption isotherms and X-ray photoelectron spectroscopy (XPS), while the related morphological analyses were conducted using scanning/transmission electron microscopy (SEM/TEM). The obtained carbons exhibit a high specific surface area up to 1801 m2 g−1 with a robust porous graphitic carbon layer structure, which provides the merits for potential application in energy storage and dye removal. We carried out potentiostatic and galvanostatic measurements using a three-electrode cell in 1.0 M H2SO4 aqueous electrolyte and achieved a specific capacitance of 118, 109.5, 101.7, 93.6, and 91.2 F g−1 at 1, 2, 4, 8 and 12 A g−1, respectively. The stability at 12 A g−1 was tested to reach 10,000 cycles with capacity retention of around 97.4%. We have demonstrated that the paper flower-derived carbons at activation temperature 800 °C (PFC-800) can be used as a promising electrode material in supercapacitor. PFC-800 can also serve as an efficient sunset yellow dye removal, showing the maximum adsorption capacity for sunset yellow (Q0, 273.6 mg g−1). © 2018 King Saud University

This present study describes the synthesis of ultrafine Bi-Sn nanoparticles decorated on carbon aerogels (Bi-Sn NP/CAG) as a nanocomposite for the electrochemical simultaneous determination of dopamine (DA) and clozapine (CLZ). The typical characterization techniques, such as XRD, Raman, BET, FT-IR, TGA, XPS, and FE-SEM/TEM, showed useful insights into the crystal phase and morphology of Bi-Sn NP/CAG. Integrated Bi-Sn NP/CAG built into a cost-effective screen printed carbon electrode (SPCE) offers a high electrochemical surface area (ECSA) compared to unmodified, Bi-Sn, and CAG/SPCEs, such that it favourably allowed the binding of DA and CLZ molecules onto the surface at the Bi-Sn/CAG, which was demonstrated by cyclic and differential pulse voltammetry techniques. As a result, the DA and CLZ sensing exhibited low detection limits (DL, 4.6 and 97.6 nM (S/N = 3)), and sensitivity (3.402 and 0.4 μA μM-1 cm-2) over a wide linear range (0.02-97.59 and 0.5-2092 μM), respectively. To go a step further, the Bi-Sn NP/CAG/SPCE was applied for the simultaneous determination of DA and CLZ which featured lower DL (23.1 and 31.3 nM (S/N = 3)), and sensitivity (0.4979 and 0.04 μA μM-1 cm-2) over a wide linear range (2-182 and 10-910 μM), respectively. The selectivity for DA and CLZ in the presence of a 10-fold concentration of their potentially interfering active species was demonstrated. Finally, this sensing methodology enables the rapid electrochemical determination of the amount of DA and CLZ in a rat brain region serum sample with successful recovery outcomes. © The Royal Society of Chemistry.

The simple and novel surfactant-free synthesis of flower-like strontium-doped nickel oxide nanorods (SNO NRs) via a simple sonochemical co-precipitation method was used for electrochemical sensing of quercetin (QCT). The structure and morphology of the as-synthesized flower-like SNO NRs were characterized using various spectroscopic techniques. Then, CV, EIS, and DPV were used to examine their electrochemical properties. The effective loading concentration, pH, scan rate and stability of the SNO NR-modified electrodes were studied. Under optimized conditions, the electrochemical detection of QCT demonstrated a low detection potential of 0.3 V (vs. Ag/AgCl), and achieved a higher oxidation peak current compared to those of other modified electrodes in PB (pH 5.0). The voltammetric current response was found to linearly increase with an increasing concentration range from 0.01-68.53 μM, along with a low detection limit of 1.98 nM, and a high sensitivity of 2.1055 μA mM cm-2. The sensor also shows good selectivity and satisfactory recovery for real sample (apple and grape juice) analysis. © 2020 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

In this work, gold nanoparticle (Au NP) decorated poly(diallyldimethylammonium chloride) (PDDA) functionalized graphene hydrogel (Au NP@PDDA/GH) nanocomposites were fabricated. The resulting materials were characterized by a variety of analytical and spectroscopic techniques. Electrochemical performances of the prepared composites were examined by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and linear sweep voltammetry (LSV). The Au NPs were decorated uniformly and densely on the GO@PDDA composite material based on the electrostatic attraction and this new hierarchical nanostructure can provide a more favourable microenvironment for electron transfer. Under the optimized conditions, the Au NP@PDDA/GH nanocomposite was used as a novel sensing probe for metronidazole (MZ) which was found to have the concentration range of 0.4-656.4 μM with a correlation coefficient (0.999, limit of detection (LOD) based on (LOD = 3k/∂) of 0.097 μM), and a sensitivity of 4.286 μA μM−1. With satisfactory selectivity, reproducibility, and stability, the nanostructure we proposed offered an alternative for electrode fabrication and MZ sensing. Au NP@PDDA/GH was also applied to the reduction of MZ and pharmacy tablets by NaBH4under ambient conditions. Thus, Au NP@PDDA/GH application provides simplicity, reliability, durability, and low cost benefits. © The Royal Society of Chemistry 2020.

The inhibition of platelet activation is considered a potential therapeutic strategy for the treatment of arterial thrombotic diseases; therefore, maintaining platelets in their inactive state has garnered much attention. In recent years, nanoparticles have emerged as important players in modern medicine, but potential interactions between them and platelets remain to be extensively investigated. Herein, we synthesized a new type of carbon dot (CDOT) nanoparticle and investigated its potential as a new antiplatelet agent. This nanoparticle exerted a potent inhibitory effect in collagen-stimulated human platelet aggregation. Further, it did not induce cytotoxic effects, as evidenced in a lactate dehydrogenase assay, and inhibited collagen-activated protein kinase C (PKC) activation and Akt (protein kinase B), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) phosphorylation. The bleeding time, a major side-effect of using antiplatelet agents, was unaffected in CDOT-treated mice. Moreover, our CDOT could reduce mortality in mice with ADP-induced acute pulmonary thromboembolism. Overall, CDOT is effective against platelet activation in vitro via reduction of the phospholipase C/PKC cascade, consequently suppressing the activation of MAPK. Accordingly, this study affords the validation that CDOT has the potential to serve as a therapeutic agent for the treatment of arterial thromboembolic disorders. © 2020 by the authors.

Since the past decade, enormous research efforts have been devoted to the detection/degradation and quantification of environmental toxic pollutants and biologically important molecules due to their ubiquitous necessity in the fields of environmental protection and human health. These fields of sensor and catalysis are advanced to a new era after emerging of nanomaterials, especially, carbon nanomaterials including graphene, carbon nanotube, carbon dots (C-dots), etc. Among them, the C-dots in the carbon family are rapidly boosted in the aspect of synthesis and application due to their superior properties of chemical and photostability, highly fluorescent with tunable, non/low-toxicity, and biocompatibility. The C-dot-based functional materials have shown great potential in sensor and catalysis fields for the detection/degradation of environmental pollutants. The major advantage of C-dots is that they can be easily prepared from numerous biomass/waste materials which are inexpensive and environment-friendly and are suitable for a developing trend of sustainable materials. This review is devoted to the recent development (since 2017) in the synthesis of biomass- and chemical-derived C-dots as well as diverse functionalization of C-dots. Their capability as a sensor and catalyst and respective mechanism are summarized. The future perspectives of C-dots are also discussed.