Polydopamine-Enabled Biomimetic Surface Engineering of Materials:New Insights and Promising Applications

Surface modification is an important approach to modify the properties of materials. Numerous approaches have been adopted to tailor the properties of such materials, which have been proven successful at many scales and parameters. However, most of these techniques are often tedious, poorly adhesive, costly, sometimes hazardous, and surface-specific, hence cannot be extended on a large scale and all kinds of surfaces. These shortcomings have led to the emergence of new dopamine (DA) based green surface modification technique where a thin polydopamine (PDA) layer is deposited on surfaces through a facile polymerization of DA under alkaline conditions to enable the surface for various applications. This surface modification strategy has several advantages over other techniques in deposition processing under mild conditions, cost-effective and straightforward ingredients, and applicability to all kinds of surfaces regardless of their sizes, shapes, and types. Moreover, the PDA layer enhances the surface functionality. Therefore, it can serve as a versatile platform for various secondary reactions for a wide range of applications. Herein, the chemistry of DA is summarized and its polymerized form PDA for the modification of different families of materials’ surfaces with an emphasis on energy, environmental and biological applications.</p

Styrene Sulphonic Acid Doped Polyaniline Based Immunosensor for Highly Sensitive Impedimetric Sensing of Atrazine

Styrene sulphonic acid (SSA) doped polyaniline (PAni) was chemically synthesized. The synthesized product SSA-PAni was treated with 3-(aminopropyl) triethoxysilane in order to achieve a functional terminal of −NH2 group. This functional nanopolymer has been electrochemically deposited on to the working area of a carbon screen printed electrode (carbon SPE). Incubation of the SSA-PAni modified carbon SPE with anti-atrazine antibodies yielded the formation of a pesticide immunosensor. This immunosensor offered specific and highly sensitive detection (limit of detection 0.01 ng/mL) of atrazine over a wide concentration range (0.01–50 ng/mL)

Robust Nanocomposite of Nitrogen-Doped Reduced Graphene Oxide and MnO₂ Nanorods for High-Performance Supercapacitors and Nonenzymatic Peroxide Sensors

The urgent demand of sustainable energy systems and reliable sensing devices has fostered the development of cost-effective, multifunctional electrode material based platforms. In this work, we have demonstrated the bifunctionality of nitrogen-doped reduced graphene oxide-MnO₂ nanocomposite (NRGO-MnO₂), toward two most diverse and challenging applications: (i) supercapacitor and (ii) peroxide sensor, which was synthesized by a facile one-pot hydrothermal method. The electrochemical investigations revealed its high specific capacitance (648 F g^–1 at 1.5 A g^–1) with remarkable rate performance (retains 80.20% up to 10 A g^–1) and long-term cyclic efficiency. Additionally, it can detect peroxide rapidly (2 s), with high sensitivity (2081 μAmM^–1 cm^–2) and a noteworthy detection limit (24 nM) in a wide dynamic range (0.4–121.2 μM). Fascinating features such as the distinguished selectivity, repeatability, and operational stability suggests its potency to be an ideal electrode for peroxide sensors. Finally, the charge transfer kinetics and capacitive components, probed by electrochemical impedance spectroscopy (EIS), are found to be in correlation with other investigations. The positive synergism between MnO₂ nanorods and NRGO induces higher conductivity and surface area, which eventually promotes superior supercapacitor and sensor performances. The results highlight NRGO-MnO₂ nanocomposite as a multifunctional, cutting edge, and sustainable material for next-generation energy storage and sensing applications

Visible-Light-Induced Water Splitting Based on a Novel α‑Fe₂O₃/CdS Heterostructure

In this work, CdS nanoparticles were grown on top of a hematite (α-Fe₂O₃) film as photoanodes for the photoelectrochemical water splitting. Such type of composition was chosen to enhance the electrical conductivity and photoactivity of traditionally used bare hematite nanostructures. The fabricated thin film was probed by various physicochemical, electrochemical, and optical techniques, revealing high crystallinity of the prepared nanocomposite and the presence of two distinct phases with different band gaps. Furthermore, photoassisted water splitting tests exhibit a noteworthy photocurrent of 0.6 mA/cm² and a relatively low onset potential of 0.4 V (vs reversible hydrogen electrode) for the composite electrode. The high photocurrent generation ability was attributed to the synergistic interplay between conduction and valence band (VB) levels of CdS and α-Fe₂O₃, which was further interpreted by <i>J</i>–<i>V</i> curves. Finally, electrochemical impedance spectroscopy investigation of the obtained films suggests that the photogenerated holes could be transferred from the VB of α-Fe₂O₃ to the electrolyte more efficiently in the hybrid nanostructure

Emerging Robust Heterostructure of MoS₂–rGO for High-Performance Supercapacitors

The intermittent nature of renewable energy resources has led to a continuous mismatch between energy demand and supply. A possible solution to overcome this persistent problem is to design appropriate energy-storage materials. Supercapacitors based on different nanoelectrode materials have emerged as one of the promising storage devices. In this work, we investigate the supercapacitor properties of a molybdenum disulfide–reduced graphene oxide (rGO) heterostructure-based binder-free electrode, which delivered a high specific capacitance (387.6 F g^–1 at 1.2 A g^–1) and impressive cycling stability (virtually no loss up to 1000 cycles). In addition, the possible role of rGO in the composite toward synergistically enhanced supercapacitance has been highlighted. Moreover, an attempt has been made to correlate the electrochemical impedance spectroscopy studies with the voltammetric analyses. The performance exceeds that of the reported state-of-the-art structures

Recurrent hemorrhagic pericardial effusion and tamponade due to filariasis successfully treated with ivermectin and albendazole

Filariasis presenting with pericardial effusion with tamponade is rare. We report a case of a 30-year-old female who was admitted with severe dyspnea and chest pain since 2 days. Echocardiogram showed massive pericardial effusion with tamponade. Pericardial fluid aspiration drained 1.2 L of hemorrhagic fluid. Cytology examination revealed microfilaria of Wuchereria bancrofti. She was treated with diethyl carbamazine and discharged. Six weeks later, she presented again with massive pericardial effusion with cardiac tamponade. Pericardiocentesis was done. Cytology examination revealed microfilaria of W. bancrofti. This time she was treated with ivermectin and albendazole and cured. Hemorrhagic effusion resolved completely. Though relatively uncommon, tropical diseases must always be considered in the etiological diagnosis of recurrent pericardial effusion

How Early-Career Scientists Responded with Resiliency to the Space Created by the COVID-19 Pandemic

10.1021/acscentsci.2c00094ACS CENTRAL SCIENCE83294-29

Probing Highly Luminescent Europium-Doped Lanthanum Orthophosphate Nanorods for Strategic Applications

Herein we have established a strategy for the synthesis of highly luminescent and biocompatible europium-doped lanthanum orthophosphate (La0.85PO4Eu0.153+) nanorods. The structure and morphogenesis of these nanorods have been probed by XRD, SEM, and TEM/HRTEM techniques. The XRD result confirms that the as-synthesized nanorods form in a monazite phase with a monoclinic crystal structure. Furthermore, the surface morphology shows that the synthesized nanorods have an average diameter of similar to 90 nm and length of similar to 2 mu m. The HRTEM images show clear lattice fringes that support the presence of better crystal quality and enhanced photoluminescence hypersensitive red emission at 610 nm (D-5(0)-F-7(2)) upon 394 nm wavelength excitation. Furthermore, time-resolved spectroscopy and an MTT assay of these luminescent nanorods demonstrate a photoluminescent decay time of milliseconds with nontoxic behavior. Hence, these obtained results suggest that the as-synthesized luminescent nanorods could be potentially used in invisible security ink and high-contrast bioimaging applications