Polymer-induced self-assembly of inorganic nanoparticles has emerged as a powerful strategy for fabrication of stimuli-responsive drug delivery nanosystems. Herein, we designed and synthesized a series of lipoic acid-capped polysarcosine-b-polycaprolactone (PSar-b-PCL) block copolymers. The self-assembly of gold nanoparticles drove by these block copolymers was systematically investigated, and the preparation of near-infrared (NIR) light-responsive PSar-decorated gold nanovesicle (PSGV) was optimized. DOX as anticancer drug was efficiently encapsulated within the cavity of PSGV. The PSGV greatly prevented doxorubicin (DOX) from premature leakage. While upon 808 nm laser irradiation, most of loaded DOX was rapidly released, along with the recovery of DOX fluorescence. Impressively, the DOX-loaded PSGV (DOX-PSGV) exhibited much higher cell uptake efficiency when compared to DOX-loaded polyethylene glycol (PEG)-coated gold nanovesicle (DOX-PEGV). Thanks to the synergistic photothermal/chemo therapy, the DOX-PSGV had highly superior antitumor efficacy in established 4T1 tumor model.

Chemical and biological sensing play important roles in healthcare, environmental science, food-safety tests, and medical applications. Flexible organic electrochemical transistors (OECTs) have shown great promise in the field of chemical and biological sensing, owing to their superior sensitivity, high biocompatibility, low cost, and light weight. Herein, we summarize recent progress in the fabrication of flexible OECTs and their applications in chemical and biological sensing. We start with a brief introduction to the working principle, configuration, and sensing mechanism of the flexible OECT-based sensors. Then, we focus on the fabrication of flexible OECT-based sensors, including material selection and structural engineering of the components in OECTs: the substrate, electrodes, electrolyte, and channel. Particularly, the gate modification is discussed extensively. Then, the applications of OECT-based sensors in chemical and biological sensing are reviewed in detail. Especially, the array-based and integrated OECT sensors are also introduced. Finally, we present the conclusions and remaining challenges in the field of flexible OECT-based sensing. Our timely review will deepen the understanding of the flexible OECT-based sensors and promote the further development of the fast-growing field of flexible sensing.

The development of artificial enzyme mimics has been rapidly growing in recent years, and it is attracting increasing attention owing to their remarkable advantages over natural enzymes. Herein, we developed a general and facile method to fabricate efficient glutathione peroxidase (GPx) mimics by grafting selenium-containing molecules (phenylselenylbromide, PhSeBr) to a Zr(IV)-based UiO-66-NH₂ framework. In the presence of glutathione (GSH) serving as substrate, the fabricated UiO-66-Se catalysts can catalyze the reduction of hydroperoxides. The as-prepared UiO-66-Se systems show good catalytic activity over three cycles. These high-efficiency GPx mimic metal-organic frameworks (MOFs) are endowed with excellent thermal and structural stability, providing a promising avenue for the development of artificial enzyme mimics.

A hybrid structure consisting of boron-doped porous carbon spheres and graphene (BPCS-G) has been designed and synthesized toward solving the polysulfide-shuttle problem, which is the most critical issue of current Li-S batteries. The proposed hybrid structure showing high surface area (870 m²·g^-1) and high B-dopant content (6.51 wt.%) simultaneously offers both physical confinement and chemical absorption of polysulfides. On one hand, the abundant-pore structure ensures high sulfur loading, facilitates fast charge transfer, and restrains polysulfide migration during cycling. On the other hand, our density functional theory calculations demonstrate that the B dopant is capable of chemically binding polysulfides. As a consequence of such dual polysulfide confinement, the BPCS-G/S cathode prepared with 70 wt.% sulfur loading presents a high reversible capacity of 1, 174 mAh·g^-1 at 0.02 C, a high rate capacity of 396 mAh·g^-1 at 5 C, and good cyclability over 500 cycles with only 0.05% capacity decay per cycle. The present work provides an efficient and cost-effective platform for the scalable synthesis of high-performance carbon-based materials for advanced Li-S batteries.

A highly active and stable oxygen evolution reaction (OER) electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni₃S₂@graphene@Co₉₂S₈ (Ni₃S₂@G@Co₉S₈), a sandwich-structured OER electrocatalyst, was grown in situ on nickel foam; it afforded an enhanced catalytic performance when highly conductive graphene is introduced as an intermediary for enhancing the electron transfer rate and stability. Serving as a free-standing electrocatalytic electrode, Ni₃S₂@G@Co₉S₈ presents excellent electrocatalytic activities for OER: A low onset overpotential (2 mA·cm^-2 at 174 mV), large anode current density (10 mA·cm^-2 at an overpotential of 210 mV), low Tafel slope (66 mV·dec^-1), and predominant durability of over 96 h (releasing a current density of ~14 mA·cm^-2 with a low and constant overpotential of 215 mV) in a 1 M KOH solution. This work provides a promising, cost-efficient electrocatalyst and sheds new light on improving the electrochemical performance of composites through enhancing the electron transfer rate and stability by introducing graphene as an intermediary.

Current research on vanadium oxides in lithium ion batteries (LIBs) considers them as cathode materials, whereas they are rarely studied for use as anodes in LIBs because of their low electrical conductivity and rapid capacity fading. In this work, hydrogenated vanadium oxide nanoneedles were prepared and incorporated into freeze-dried graphene foam. The hydrogenated vanadium oxides show greatly improved charge-transfer kinetics, which lead to excellent electrochemical properties. When tested as anode materials (0.005–3.0 V vs. Li/Li⁺) in LIBs, the sample activated at 600 ℃ exhibits high specific capacity (~941 mA·h·g^-1 at 100 mA·g^-1) and high-rate capability (~504 mA·h·g^-1 at 5 A·g^-1), as well as excellent cycling performance (~285 mA·h·g^-1 in the 1, 000^th cycle at 5 A·g^-1). These results demonstrate the promising application of vanadium oxides as anodes in LIBs.

In this work, single- and double-shelled NiCo₂O₄ hollow spheres have been synthesized in situ by a one-pot solvothermal method assisted by xylose, followed by heat treatment. Employed as supercapacitor electrode materials, the double-shelled NiCo₂O₄ hollow spheres exhibit a remarkable specific capacitance (1, 204.4 F·g^-1 at a current density of 2.0 A·g^-1) and excellent cycling stability (103.6% retention after 10, 000 cycles at a current density of 10 A·g^-1). Such outstanding electrochemical performance can be attributed to their unique internal morphology, which provides a higher surface area with a larger number of active sites available to interact with the electrolyte. The versatility of this method was demonstrated by applying it to other binary metal oxide materials, such as ZnCo₂O₄, ZnMn₂O₄, and CoMn₂O₄. The present study thus illustrates a simple and general strategy for the preparation of binary transition metal oxide hollow spheres with a controllable number of shells. This approach shows great promise for the development of next-generation high-performance electrochemical materials.

Therapeutic nanoparticles (NPs) based on the donor-acceptor-donor structured small organic molecule diketopyrrolopyrrole (SDPP) were prepared using a simple reprecipitation approach. These near-infrared radiation-absorbing NPs have high photothermal conversion efficiency and are able to selectively target cancer tissues through the enhanced permeability and retention effect. Benefiting from these advantages, SDPP NPs can serve as an excellent therapeutic agent for highly efficient and noninvasive photoacoustic imaging-guided photothermal therapy. Experiments using mouse tumor models showed that the SDPP NPs exhibited exceptional tumor ablation ability under laser irradiation (660 nm, 1.0 W·cm^-2), even at a low dose (0.16 mg·kg^-1).

The rational design of earth-abundant catalysts with excellent water splitting activities is important to obtain clean fuels for sustainable energy devices. In this study, mixed transition metal oxide nanoparticles encapsulated in nitrogendoped carbon (denoted as AB₂O₄@NC) were developed using a one-pot protocol, wherein a metal–organic complex was adopted as the precursor. As a proof of concept, MnCo₂O₄@NC was used as an electrocatalyst for water oxidation, and demonstrated an outstanding electrocatalytic activity with low overpotential to achieve a current density of 10 mA·cm^-1 (η₁₀ = 287 mV), small Tafel slope (55 mV·dec^-1), and high stability (96% retention after 20 h). The excellent electrochemical performance benefited from the synergistic effects of the MnCo₂O₄ nanoparticles and nitrogen-doped carbon, as well as the assembled mesoporous nanowire structure. Finally, a highly stable all-solid-state supercapacitor based on MnCo₂O₄@NC was demonstrated (1.5% decay after 10, 000 cycles).

Triangular Ni(HCO₃)₂ nanosheets were synthesized via a template-free solvothermal method. The phase transition and formation mechanism were explored systematically. Further investigation indicated that the reaction time and pH have significant effects on the morphology and size distribution of the triangular Ni(HCO₃)₂ nanosheets. More interestingly, the resulting product had an ultra-thin structure and high specific surface area, which can effectively accelerate the charge transport during charge-discharge processes. As a result, the triangular Ni(HCO₃)₂ nanosheets not only exhibited high specific capacitance (1, 797 F·g^-1 at 5 A·g^-1 and 1, 060 F·g^-1 at 50 A·g^-1), but also showed excellent cycling stability with a high current density (~80% capacitance retention after 5, 000 cycles at the current density of 20 A·g^-1).