The ongoing surge in demand for sustainable energy technologies with little to no environmental impacts calls for the exploration of advanced energy storage materials. Inspiration from nature is undoubtedly a promising approach to comply with environmental legislations. Herein, we describe a facile and green electrosynthesis approach to fabricate a polydopamine (PDA) nanofilm supported on oxygen-functionalized carbon cloth (FCC). The surface functionalization of carbon cloth facilitates the PDA nanofilm adhesion and endows the as-prepared PDA-FCC electrode with excellent flexibility, good electrical conductance (22.6 mS), and outstanding wettability to the aqueous electrolyte. Owing to these merits, the PDA-FCC electrode delivers a favorabl

Mesoporous carbon nitrides (MCNs) are considered as one of the most fascinating materials for a variety of applications because of their low cost, high specific surface area, abundant functionalities, and ordered porous structures. However, pristine MCNs suffer from a poor electrical conductivity, thus an inferior supercapacitive performance. Herein, we synthesized MCN via a nano hard-templating approach (using SBA-15 template) and then composited it with the graphene aerogel (GA). The highly conductive metal-free MCN-GA nanocomposite, in which MCN is firmly grafted onto GA via covalent bonding, exhibits a hierarchical porous structure, and demonstrates an exceptional supercapacitive performance among the different materials of the carbon f

The surging interest in high performance, low‐cost, and safe energy storage devices has spurred tremendous research efforts in the development of advanced electrode active materials. Herein, the in situ growth of zinc–iron layered double hydroxide (Zn–Fe LDH) on graphene aerogel (GA) substrates through a facile, one‐pot hydrothermal method is reported. The strong interaction and efficient electronic coupling between LDH and graphene substantially improve interfacial charge transport properties of the resulting nanocomposite and provide more available redox active sites for faradaic reactions. An LDH–GA||Ni(OH)2 device is also fabricated that results in greatly enhanced specific capacity (187 mAh g−1 at 0.1 A g−1), outstanding

The development of efficient drug delivery and imaging approaches is of great importance for both diagnostic and therapeutic purposes. This is especially important for the triple-negative breast cancers for which chemotherapy is often the mainstay of treatment. Metal-organic frameworks (MOFs) have recently attracted tremendous attention as nanocarriers that can be loaded with a wide variety of therapeutic as well as bioimaging agents. Herein, the Fe3O4 core UiO-66-NH2 MOF shell nanostructures, Fe3O4@MOF, were loaded with the anticancer drug doxorubicin (DOX), and the loaded nanostructures were conjugated to highly fluorescent carbon dots (CDs) and then capped with the nucleolin-binding aptamer, AS1411. The Fe3O4@MOF-DOX-CDs-Apt nanocarriers

High power performance with the ability to be charged in a matter of seconds have made supercapacitors the technology of choice for cutting-edge applications. However, improving the energy content of supercapacitors is necessary to contribute to the technological advancement of energy storage devices. Herein, we report the synthesis of two transition metal spinel oxide-reduced graphene oxide (rGO) nanocomposites; namely CuCo2O4-rGO and CoFe2O4-rGO. The CuCo2O4-rGO nanocomposite as a positive electrode exhibits an extremely high specific capacitance of 2064.0?F?g−1 at 2?A?g−1, whereas the CoFe2O4-rGO nanocomposite as a negative electrode shows a specific capacitance of 261.0?F?g−1 at 2?A?g−1. The asymmetric CoFe2O4-rGO//CuCo2O4-rGO d

The oxidation states of polymers and their stabilities are of great importance for their application in energy storage systems. In this paper, we report an air-stable triphenylamine-triazine-based conjugated microporous polymer (pTTPATA) with the smart function of changing color by simply changing the applied voltage. Uniquely, the yellow colored neutral polymer switches to a red color upon oxidation (p-doping) and the red color remains stable even for ten hours after removal of the applied potential, which allows an in-depth analysis of the pTTPATA in the oxidized state. X-ray photoelectron spectroscopy (XPS) confirms that large amounts of radical cations from the triazine groups as well as a small proportion of those from oxidatized triph

Over the past decade, electrochemical energy storage (EES) devices have greatly improved, as a wide variety of advanced electrode active materials and new device architectures have been developed. These new materials and devices should be evaluated against clear and rigorous metrics, primarily based on the evidence of real performances. A series of criteria are commonly used to characterize and report performance of EES systems in the literature. However, as advanced EES systems are becoming more and more sophisticated, the methodologies to reliably evaluate the performance of the electrode active materials and EES devices need to be refined to realize the true promise as well as the limitations of these fast-moving technologies, and target

The pursuit of new negative electrode materials for redox supercapacitors with a high capacitance, boosted energy, and high rate capability is still a tremendous challenge. Herein, we report a Nile Blue-conjugated graphene aerogel (NB-GA) as a negative electrode material with excellent pseudocapacitive performance (with specific capacitance of up to 483 F g-1 at 1 A g-1) in all acidic, neutral and alkaline aqueous electrolytes. The contribution from capacitive charge storage represents 93.4% of the total charge, surpassing the best pseudocapacitors known. To assess the feasibility of NB-GA as a negative electrode material across the full pH range, we fabricated three devices namely, a symmetric NB-GA//NB-GA device in an acidic (1.0 M H2SO4)

Major technological challenges in point-of-care diagnostics are in the development of simple, fast, and inexpensive methods for high-throughput and multiplexed genotyping of single-nucleotide polymorphisms (SNPs). Herein, we develop a facile SNP detection platform based on platinum nanoparticles–induced etching of gold nanorods (AuNRs) by H2O2. The IVS-II-1 (G>A) β-thalassemia mutation, as one of the most prevalent mutations in the Middle East, was used as a model disease. In the presence of H2O2, ferrous ion (Fe2+) triggers a Fenton reaction with the catalytic decomposition of H2O2 into highly reactive hydroxyl (HO?) and hydroperoxyl (HOO?) radicals. These species etch AuNRs along the longitudinal axes to short AuNRs or eve

Herein, we report the one-pot co-synthesis of a novel water-stable nickel-based metal-organic framework (Ni-MOF) with a Co-MOF, as well as the dual Ni/Co-MOF-reduced graphene oxide (rGO) nanocomposite in the same reaction vessel. Introduction of the two metal precursors along with the organic linker in the same reaction vessel guarantees in situ homogeneously distributed MOF particles in the nanoscale level that cannot be obtained by physical mixing of the MOFs synthesized individually. The Ni/Co-MOF-rGO nanocomposite demonstrates a high specific capacitance of 860 F/g at 1.0 A/g. The asymmetric activated carbon//Ni/Co-MOF-rGO device delivers specific energy of 72.8 Wh/kg at 850 W/kg, and still holds 15.1 Wh/kg under the high specif

With rising energy consumption in the world and the negative environmental and human health impacts of fossil fuels, the demand for renewable energy sources is increasing. The energy generated by renewable energy sources can be stored either in a chemical (water splitting) or an electrochemical (battery or supercapacitor) form, that are two distinct processes. Here, we introduce an integrated solar-powered system for both electrochemical energy storage and water electrolysis. A nickel-cobalt-iron layered double hydroxide (Ni-Co-Fe LDH) was successfully synthesized on nickel foam as a substrate using a fast, one-step electrodeposition approach. The Ni-Co-Fe LDH exhibited excellent electrochemical properties both as an active electrode materi

Discovering efficient pseudocapacitive charge storage materials has become one of the grand challenges to reduce the gap between high energy density batteries and high power density and durable electrical double‐layer capacitors. This research direction is facilitated by the introduction of redox‐active species that add Faradaic charge storage to the system. However, the astonishing abilities of organic redox species to increase energy density are insufficient to compensate for their poor electrical conductivity and inferior cyclability. Herein, it is proposed that these challenges can be simultaneously met by thoughtful selection of a redox species, thionine, that can be conjugated to a 3D graphene aerogel as a substrate via π–π i

While the market for supercapacitors is rapidly growing due to their high power density, their low energy density compared to batteries represents a great barrier for the future of this technology. The poorly understood chemistry of electrode-electrolyte interfaces implies that there is substantial room for improvement through a careful design of the materials involved. Here we present a unique approach for improving the energy density of supercapacitors through redox additive-assisted electrocatalytic in situ regeneration of the electrode active materials. By utilizing a quinone-based redox electrolyte and a nanostructured conjugated polyaniline electrode, we continually regenerate the reactants, resulting in a redox supercapacitor having

Supercapacitors (SCs), as high power density energy storage resources, have recently attracted considerable attention. Increasing the energy of supercapacitors is a key parameter to success in achieving far more demanding energy storage applications. There are two approaches to achieve this goal: the first is to widen the operating potential window, and the second is to develop emerging capacitive or pseudocapacitive materials. Polyaniline (PANI) with different morphologies, and hence different supercapacitive performances, has been considered as one of the intriguing active materials due to its high conductivity, intrinsic flexibility, and high redox active specific capacitance. In this work, we report on a simple and convenient method to

Aqueous supercapacitors based on neutral solutions have the advantages of high-ionic conductivity, being environmentally friendly, safe, and low cost. However, the operating potential window for most aqueous electrolytes is far lower than that of organic electrolytes that are commonly used in commercial supercapacitors. In this work, we report on the fabrication of a wide potential window, high-energy aqueous asymmetric supercapacitor, without sacrificing power, by using a nanostructured LiMn2O4/reduced graphene oxide (LMO–rGO) nanocomposite. We synthesized the uniformly distributed LMO in the LMO–rGO nanocomposite using a co-precipitation route followed by a low-temperature hydrothermal treatment. In a three-electrode ce

Immobilization of biomolecules with a proper orientation is considered as a basis for diverse biotechnological applications. Herein, we report a host‐guest inclusion complexation between β‐cyclodextrin (β‐CD) and biotin as a versatile approach for the immobilization of biomolecules. As a practical application, a sandwich‐type electrochemical immunosensor was designed for the determination of prostate specific antigen (PSA). The immunosensor was fabricated by in situ electropolymerization of poly(N‐acetylaniline) onto a rGO‐modified Pt electrode. Then, β‐CD was covalently grafted onto the over‐oxidized polymer backbone. For improving the efficiency of the assay, AuNPs were casted on the polymeric film, on the surface of

We report here a new electrochemical probe for the development of a sensitive, and selective sandwich‐type electrochemical immunosensor for the detection of epidermal growth factor receptor (EGFR). The probe is a newly synthesized bovine serum albumin (BSA)‐templated Pb nanocluster (PbNC@BSA). For fabrication of the immunosensor, we employed streptavidin‐coated magnetic beads (MB) as a platform for immobilization of the biotinylated primary antibody (Ab1), and utilized the PbNC@BSA conjugated to secondary antibody (Ab2) as a signaling probe. After sandwiching the target protein between Ab1 and Ab2, we dissolved PbNC@BSA into an acid, and recorded square wave anodic stripping voltammetric (SWASV) signal of the Pb ions as an analytical