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Metal–organic frameworks (MOFs) are novel inorganic–organic hybridized crystals with a wide range of applications. In the last twenty years, fluorescence sensing based on MOFs has attracted much attention. MOFs can exhibit luminescence from metal nodes, ligands or introduced guests, which provides an excellent fluorescence response in sensing. However, single-signal emitting MOFs are susceptible to interference from concentration, environment, and excitation intensity, resulting in poor accuracy. To overcome the shortcomings, dual-emission MOF-based ratiometric fluorescence sensors have been proposed and rapidly developed. In this review, we first introduce the luminescence mechanisms, synthetic methods, and detection mechanisms of dual-emission MOFs, highlight the strategies for constructing ratiometric fluorescence sensors based on dual-emission MOFs, and classify them into three categories: intrinsic dual-emission and single-emission MOFs with luminescent guests, and non-emission MOFs with other luminescent materials. Then, we summarize the recent advances in dual-emission MOF-based ratiometric fluorescence sensors in various analytical industries. Finally, we discuss the current challenges and prospects for the future development of these sensors. [ABSTRACT FROM AUTHOR]

The development of fibers and textiles span the entire history of human science and technology as well as civilization. The emerging wearable electronics is attracting enormous attention compared with traditional rigid and brittle devices, as it could conform to the curved human body with complex morphology and adapt to intense movements naturally. Smart fibers and textiles are highly desirable due to their attractive properties such as lightweight, breathability, weavability, stretchability, and excellent adaptability to arbitrary mechanical deformations during daily human activities. Furthermore, smart fibers and textiles have been regarded as ideal building blocks to weave flexible and stretchable electronics, which holds great promise in emerging clothe-based wearable applications. This review comprehensively summarizes the state-of-the-art achievement and advancement of smart fibers and textiles for emerging wearable electronics, including fiber/textile-based breathable substrates, conductive materials, manufacturing methods and their applications in emerging wearable electronics such as stretchable conductive fibers, soft sensors, personal healthcare, entertainment and thermal management. We mainly focus on smart fibers and textiles with high-comfort wearing experience and intelligent functions, which could seamlessly integrate the advantages of traditional clothes and electronic devices, and discuss the strategies and mechanisms that are suitable for fabricating high-performance smart fibers and textiles with excellent mechanical deformability and wearable reliability. Finally, critical analysis on the opportunities, challenges as well as future development directions of smart fibers and textiles in emerging clothe-based wearable electronics are also presented. [ABSTRACT FROM AUTHOR]

Zr-metal–organic frameworks (Zr-MOFs) have received increasing interest for their use as the signal marker in the development of sandwich-structured aptasensors for the detection of exosomes. However, Zr4+ ions of the Zr-MOFs can interact with not only the exosomes, but also the aptamers, leading to possible false positives and a large background response. In the present study, we report for the first time aptasensors with Pd nanoparticle (NP)-decorated and hemin-embedded UiO-66 MOFs serving as the signal amplification marker to eliminate false positives and decrease the background response of aptasensors. To construct aptasensors for detection of exosomes, CD63-specific aptamers were tethered onto magnetic Fe3O4 particles coated with polydopamine (PDA) and UiO-66-NH2 using glutaraldehyde crosslinking for capturing the exosomes. To prepare highly catalytic Zr-MOF-based signal markers, UiO-66 MOFs were modified with hemin followed by Pd NPs. The as-prepared Pd-decorated hemin-embedded MOFs showed high catalytic activity towards the chromogenic oxidation reaction of TMB by H2O2. Moreover, the decoration with Pd NPs led to the change of the surface charge state of the catalytic hemin-embedded UiO-66 MOFs from positive to negative, weakening the interaction between the signal marker and the negatively charged aptamers. Therefore, the as-prepared aptasensors showed an improved sensing performance towards exosomes with a linear concentration range from 4.28 × 102 to 4.28 × 105 and a limit of detection (LOD) of 86.2 particles per μL. The as-prepared aptasensors also showed high sensitivity and selectivity to the exosomes from different origins including the HeLa cell line and MCF-7 cell line. [ABSTRACT FROM AUTHOR]

Preeclampsia (PE) seriously affects pregnant women and fetuses' health and causes maternal near-misses. CD81 has been confirmed to be a novel PE biomarker with great potential. Herein, a hypersensitive dichromatic biosensor based on the plasmonic enzyme-linked immunosorbent assay (plasmonic ELISA) is proposed initially for the application of CD81 in early screening for PE. In this work, a novel chromogenic substrate [(HAuCl4)-(N-methylpyrrolidone)-(Na3C6H5O7)] is designed based on the H2O2 dual catalysis reduction pathway of Au ions. The two reduction pathways of Au ions are controlled by H2O2 which ensures that the synthesis and growth of AuNPs are sensitive to H2O2. The amount of H2O2 correlates with the concentration of CD81 and directs the production of different-sized AuNPs in this sensor. Blue solutions are generated when analytes are present. When analytes are absent, solutions turn red. Therefore, due to different absorption peaks in red and blue, bimodal detection can be performed, and then two detection signals can be generated, one on signal at 550 nm and another off signal at 600 nm. This method exhibits a linear response to the logarithmic CD81 concentrations in the range of 0.1–1000 pg mL−1 with detection limits of 86 fg mL−1 and 152 fg mL−1 at two wavelengths. The false positive rate is low due to the nonspecific coloration caused by serum, which produces a more intense color contrast. The results indicate that the proposed dichromatic sensor could be used as a visual sensing platform for the direct detection of CD81 in biological samples and demonstrate its potential in preeclampsia diagnosis. [ABSTRACT FROM AUTHOR]

In the present study, a mediator release test (MRT) strategy has been designed for the photoluminescent sensing of glutathione (GSH). On the basis of the redox reaction of GSH and cerium-based nanosheets (Ce(CO3)2 NSs), Ce3+ ions were released to act as a mediator for the photoluminescence emission of the Au–thiolate complexes through an aggregation-induced emission (AIE) process. Remarkably, AIE was also accompanied by high chirality for the in situ synthesis of AuNCs using Ce(CO3)2 NSs as a template and GSH as a releaser for oligomeric Au–thiolate complexes. Multiple characterization techniques, including high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), selected-area electron diffraction (SAED), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), were employed to check the structure and morphology of the Ce(CO3)2 NSs as well as the successful in situ fabrication of the AuNCs. Using this new MRT strategy, an eco-friendly, selective, biocompatible and label-free AIE probe was established for the sensitive sensing of GSH with a limit of detection (LOD) of 1.02 μM. Moreover, this switch-on luminescent nanoplatform of the conjugate probe of Au–thiolate/Ce-based NSs was successfully applied for the selective and reliable GSH detection in human serum samples. [ABSTRACT FROM AUTHOR]

Emerging soft electronics with excellent mechanical flexibility and conformability can integrate with the human body and clothes seamlessly compared with traditional rigid and bulky electronics. One-dimensional (1D) soft fibrous electronics are highly desirable due to their attractive properties such as lightweight, weaveability, stretchability as well as the ability to adapt frequent mechanical deformations during human activities. Moreover, 1D fibrous electronics have become one of the most important building blocks for weaving flexible and stretchable electronic devices, which holds great potential in practical wearable applications to weave a magnificent world. Here, the state-of-the-art advancement and development in 1D fibrous stretchable and wearable electronics are reviewed, including conductive material systems and structure design strategies, as well as their applications in wearable electronic devices such as conductive fibers, supercapacitors and batteries, and strain sensors. Finally, the critical consideration of the opportunities and challenges of 1D fibrous electrodes and devices for stretchable and wearable electronics are also presented. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn/ZnSO4/MnO2 batteries, due to their high performance and safety, have attracted much attention as promising candidates for grid-scale energy storage. Despite intensive efforts in previous studies, the cathode electrochemistry remains largely unidentified. We observed new insights into the cathode electrochemistry in Zn/ZnSO4/MnO2 batteries and found that, regardless of the physicochemical states of manganese in the pristine, as-prepared cathode, birnessite is the fated compound. The birnessite consisted of both Mn(III) and Mn(IV) with Zn2+ as the foreign cation. Birnessite stores energy via chemical redox reactions. Mn(III) has the highest priority for discharge. Mn(IV) discharges stepwise, first to MnO–OH, and then MnO–OH continuously discharges to Mn2+. During recharge, birnessite is produced stepwise via Mn2+ → MnO–OH and MnO–OH → birnessite. Zinc sulphate hydroxide plays essential roles in driving discharge and recharge via its formation with hydroxyl ions (by-products of discharge) and via neutralization of proton ions (by-products of recharge). We inserted birnessite into three-dimensional networks of single-walled carbon nanotubes (3D-SWCNT-networks) via electrochemical deposition and the superior conductive properties of the birnessite/3D-SWCNT-networks have extended the cycling numbers of the rechargeable aqueous Zn/ZnSO4/MnO2 batteries over 11 000 with a capacity retention > 82.5% at a high discharge/recharge rate of 1.5 A g−1. The rechargeable aqueous Zn/ZnSO4/MnO2 batteries with birnessite/3D-SWCNT-networks as cathodes are the promising devices for applications in long-term energy storage. [ABSTRACT FROM AUTHOR]

Thin carbon nanofibers (TCNFs) hanging on branched carbon nanofibers (3D TCNF/CNF) with an N-doping level up to 8.7 at% for high-performance supercapacitors are designed and synthesized. TCNF/CNF shows a 3D hierarchical porous structure, a large surface area, abundant ionic-channels, and a great number of electrochemically active sites by N-doping. Because of the multiple synergistic effects of these features, the supercapacitors (SCs) based on TCNF/CNF show a remarkably excellent electrochemical behavior with a high specific capacitance of 224 F g−1. After 50 000 cycles of charge/discharge, 92% of the initial capacitance value is retained in 1.0 M H2SO4 electrolyte. Moreover, the TCNF/CNF-based SCs show low internal resistance, leading to a high power density with a relatively high energy density. [ABSTRACT FROM AUTHOR]

Recent advances in wearable sweat sensors with noninvasive health monitoring capabilities have provided enormous potential for point-of-care testing (POCT) diagnostics and personalized medicine. In this paper, we present a flexible, self-healable, adhesive and wearable hydrogel patch for on-demand sweat colorimetric detection. Such a user-specific wearable hydrogel patch is simply prepared by the solvent displacement method, and can directly attach to human skin for in situ sweat sampling and colorimetric analysis without any complicated preparation steps. This wearable hydrogel patch shows excellent reliability and stability for measuring pH (4–9), glucose (0–2 mM), Cl− (0–100 mM) and Ca2+ (0–16 mM) in human sweat through integration with smartphones. The analysis and detection of multiple sweat biomarkers of 15 healthy volunteers have been successfully realized by effectively converting the analyte concentration into RGB digital signals through the wearable hydrogel patch. Such a wearable hydrogel patch with flexible, self-healable, adhesive properties can achieve on-demand in situ sweat colorimetric detection, holding great potential in point-of-care devices. [ABSTRACT FROM AUTHOR]

Endogenous H2O2 generated by a single HeLa cell that was adhered on the PDA-coated PDMS substrates under 25 mM glucose culture conditions was detected using a home-built photoelectric dual detection platform. With PMA as the stimulus, the cell released a small amount of H2O2 and its mitochondrial membrane potential (MMP) decrease was smaller, compared with that on the PDMS substrates. [ABSTRACT FROM AUTHOR]

The novel human infectious coronaviruses (CoVs) responsible for severe respiratory syndromes have raised concerns owing to the global public health emergencies they have caused repeatedly over the past two decades. However, the ongoing coronavirus disease 2019 (COVID-19) pandemic induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has received unprecedented attention internationally. Monitoring pathogenic CoVs in environmental compartments has been proposed as a promising strategy in preventing the environmental spread and tracing of infectious diseases, but a lack of reliable and efficient detection techniques is still a significant challenge. Moreover, the lack of information regarding the monitoring methodology may pose a barrier to primary researchers. Here, we provide a systematic introduction focused on the detection of CoVs in various environmental matrices, comprehensively involving methods and techniques of sampling, pretreatment, and analysis. Furthermore, the review addresses the challenges and potential improvements in virus detection techniques for environmental surveillance. [ABSTRACT FROM AUTHOR]

Distance-based detection methods with a quantitative readout are of great significance to point-of-care testing (POCT), are low-cost and user-friendly, and can be integrated into portable analytical devices. Here, we submit a visual quantitative distance-based sensor by capillary force alteration in a capillary tube. This sensor converts the wettability alteration caused by the target molecules into a capillary rise height signal. Moreover, the sensor profits from isothermal amplification technology, achieving the detection of miRNAs with high sensitivity and specificity by visually reading the height of the water in the capillary tube. The proposed biosensor shows great potential in routine clinical diagnosis as well as POCT in resource-limited settings. [ABSTRACT FROM AUTHOR]

An electrochemiluminescence approach based on surface-initiated reversible addition–fragmentation chain transfer (SI-RAFT) was developed for miRNA-21 detection for the first time. The SI-RAFT polymerization generates polymer chains with functional groups that are used to recruit luminol, enabling strong ECL signal output with low concentrations of miRNA-21, and greatly improving the detection sensitivity. [ABSTRACT FROM AUTHOR]

A fast and simple strategy for the detection of DNA based on a new type of electrochemical Zr(IV) signaling probe is reported. Briefly, this DNA biosensor was fabricated by covalently coupling the amino groups of peptide nucleic acid (PNA) probes with aldehyde groups on the surface of a glassy carbon electrode (GCE), for specifically capturing target DNA (tDNA). After this, Zr(IV) probes were attached to the phosphate groups of DNA directly with strong coordination interaction, and stoichiometrically labeled Zr(IV) probes can be detected via differential pulse voltammetry (DPV). Under optimized conditions, this strategy showed a good linear response from 0.01 nM to 100 nM tDNA, and the detection limit was 0.81 pM (R2 = 0.998). Moreover, this DNA biosensor is also successfully applied to the DNA detection in serum samples with satisfactory results and shows great potential in clinical analysis. [ABSTRACT FROM AUTHOR]

We report an easy and efficient approach based on a target-induced molecular-switch on triple-helix DNA (THD)-functionalized carbon nanotubes (CNTs) for the simultaneous visual detection of nucleic acids and proteins with a lateral flow nucleic acid biosensor. The assay had the capability to detect a minimum of 25 pM target DNA and 0.25 nM thrombin simultaneously within 20 min. [ABSTRACT FROM AUTHOR]

Superhydrophilic and superhydrophobic surfaces are prevalent in nature and have received tremendous attention due to their importance in both fundamental research and practical applications. With the high interdisciplinary research and great development of microfabrication techniques, artificial wettable–nonwettable micropatterns inspired by the water-collection behavior of desert beetles have been successfully fabricated. A combination of the two extreme states of superhydrophilicity and superhydrophobicity on the same surface precisely, wettable–nonwettable micropatterns possess unique functionalities, such as controllable superwetting, anisotropic wetting, oriented adhesion, and other properties. In this review, we briefly describe the methods for fabricating wettable–nonwettable patterns, including self-assembly, electrodeposition, inkjet printing, and photolithography. We also highlight some of the emerging applications such as water collection, controllable bioadhesion, cell arrays, microreactors, printing techniques, and biosensors combined with various detection methods. Finally, the current challenges and prospects of this renascent and rapidly developing field are proposed and discussed. [ABSTRACT FROM AUTHOR]

Chemical and biological/biochemical sensors are capable of generating readout signals that are proportional to the concentration of specific analytes of interest. Signal sensitivity and limit of detection/quantitation can be enhanced through the use of polymers, nanomaterials, and their hybrids. Of particular interest are stimuli-responsive polymers and nanomaterials due to their ability to change their physical and/or chemical characteristics in response to their environment, and/or in the presence of molecular/biomolecular species of interest. Their individual use for sensing applications have many benefits, although this review focuses on the utility of stimuli-responsive polymer and nanomaterial hybrids. We discuss three main topics: stimuli-responsive nanogels, stimuli-responsive network polymers doped with nanomaterials, and nanoparticles modified with stimuli-responsive polymers. [ABSTRACT FROM AUTHOR]

In this paper, an ultrasensitive, highly selective and green electrochemical biosensor for quantifying DNA sequences (aM DNA) based on a MnTBAP catalyst for AGET ATRP reaction is proposed. For the first time, a combination of biomimetic catalyzed free radical polymerization and DNA electrochemical biosensing was used as a signal amplification strategy. [ABSTRACT FROM AUTHOR]

The discrimination of living and dead cells shows great importance in the development of biology, pathology, medicine, and pharmacology research. Herein, we synthesized a simple benzothiazole-based probe, EP, which was characterized via1H NMR (hydrogen nuclear magnetic resonance) spectroscopy, 13C NMR (carbon nuclear magnetic resonance) spectroscopy and HRMS (high-resolution mass spectroscopy). The fluorescence changes in response to esterase were characterized via fluorescence spectroscopy. EP exhibited a 70-fold fluorescence enhancement in the presence of esterase and possessed a very low limit of detection (4.73 × 10−5 U mL−1). EP also showed high selectivity to esterase compared to other biological species. Bright fluorescence appeared in living cells, which was activated by esterase when incubated with EP. In paraformaldehyde or H2O2 pretreated cells, the fluorescence became very weak since esterase became inactive in these cells. In summary, the EP probe can monitor esterase activity both in vitro and in living cells and can be used to evaluate the health status of cells and discriminate living and dead cells effectively. [ABSTRACT FROM AUTHOR]

A programmable molecular beacon (MB) with a good discrimination capability for mature and precursor microRNAs was loaded onto the surface of Mo2C quantum dots (QDs) for accurate detection of intracellular mature microRNAs. [ABSTRACT FROM AUTHOR]

A novel fluorescence proximity assay (FPA) based on a metal–organic framework (MOF) platform is developed for highly sensitive and selective detection of target protein. [ABSTRACT FROM AUTHOR]

The bioinspired micropatterns exhibit outstanding capacity in controlling and patterning microdroplets, which have offered new functionalities and possibilities towards a wide variety of emerging biological and biomedical applications. By taking the advantages of the microdroplet anchoring ability, enrichment ability, and the accessibility of such bioinspired micropatterns, the selected topic mainly focuses on the important aspects related to (super)wettable surfaces and their emerging sensing applications (DNA, miRNA, proteins, etc.) by combining them with multiple signal output approaches (fluorescence, colorimetric, SERS, electrochemical, etc.). In the end, we also provide a personal perspective on the future development, and address the remaining challenges in the commercialization of (super)wettable micropatterns towards biosensing. [ABSTRACT FROM AUTHOR]

3D hierarchical nanocomposites always lead to excellent electrochemical properties. In this research, we have successfully designed and synthesized a hierarchical three-dimensional cobalt sulfide encapsulated carbon nanotube/carbon nanofiber (Co9S8@CNT/CNF) composite, resulting in a high-performance supercapacitor with an unrivalled capacitance of ≈1580 F g−1 at a current density of 1 A g−1. An asymmetric supercapacitor (ASC) based on these 3D hierarchical Co9S8@CNT/CNF composites exhibits a maximum energy density of 58 W h kg−1 at a power density of 1000 W kg−1 and maintains it at 38 W h kg−1 at a higher power density of 16.7 kW kg−1. Even after 10 000 charge/discharge cycles, the ASC still retains 93% of the initial capacitance at a current density of 5 A g−1. A large number of aligned CNF nanochannels combined with the synergistic effects of cobalt sulfide nanowires encapsulated in CNTs obviously accelerates the ion transfer speed and shortens the ion transfer distance, thereby boosting both power density and energy density. [ABSTRACT FROM AUTHOR]

A nanodendritic gold/graphene-based biosensor that can perform fluorescence, SERS and electrochemical tri-modal miRNA detection in a single microdroplet has been developed. The biosensor was used to successfully perform tri-modal quantitative trace miRNA-375 detection, which enormously reduces false positive readings caused by interference and ambiguous signals, and has significant implications for use in precise physiological and pathological diagnosis. [ABSTRACT FROM AUTHOR]

Construction of biocompatible functional nanocarrier for combination of chemo-photothermal therapy against cancer is cumulatively desirable, but still challenging, particularly in biodegradability and cap-free release fields. Herein, we synthesized a drug delivery system with cap-free and pH/redox-responsive properties by coating disulfide-bridged silica shell on CuS nanoparticles and simultaneously introducing hydrophobic nanochannels to seal doxorubicin (abbreviated as DMDBCP). The hydrophobic phenylamine-functionalized nanochannels on silica shell protected doxorubicin from being wetted by neutral solution in the transport process and released sealed doxorubicin after being protonated in acidic environment of cancer cells. Meanwhile, under the stimulation of plentiful glutathione in A549 cells, the disulfide-bridged structure was biodegradable, efficiently increasing the intracellular accumulation of doxorubicin to generate high cytotoxicity and shorten the retention time of nanocarriers. Furthermore, as a prominent photothermal therapy agent, CuS converted the near-infrared (NIR) optical energy to hyperthermia to ablate cancer cells and help doxorubicin release. Differing from the physical-blockage controlled release system, our cap-free system skillfully bypassed the capping units to achieve the pH/glutathione dual-responsive drug release, minimizing the adverse effects in transit. More importantly, this system achieved excellent therapeutic effect through the combination of chemo-photothermal therapy, and showed promising potential in clinical translation in the treatment of cancer. [ABSTRACT FROM AUTHOR]

Water wetting behavior in nanometer dimensions is of great importance to the signal transmission and substance transport of organisms, e.g., aquaporins on cell membranes. A biological channel can control the transport of water and ions by regulating channel wettability, which results from the transition between the intrinsic hydrophobic state and the stimulus-induced hydration state. Inspired by aquaporins in nature, herein, a biomimetic free-blocking on-demand delivery system is proposed, which is constructed by controlling the wettability of the inner surface of nanochannels of mesoporous silica nanoparticles (MSNs). Such a system is completely different from the traditional physically occluding pore controlled release system. It circumvents the use of other extra capping agents, thus overcoming the limitations of the traditional nano “gate” blockage system with inherent instability, poor plugging capability and low biocompatibility. Additionally, further applications in drug delivery have shown that this system can selectively release entrapped drugs in beta cells triggered by intracellular glucose in a controlled manner but not in normal cells. This hydrophobic gating drug delivery system with simple and effective performance provides a new opportunity for constructing a mass transport platform from the perspective of surface wettability. [ABSTRACT FROM AUTHOR]

Capillarity is an extremely common physical–chemical phenomenon related to wettability in nature, which has wide theoretical and practical interest. Herein, we reported a facile sensing device based on capillary force change in a vertical capillary tube. In this height-based capillary sensor (HCS), the inner surface of the capillary tube was modified with a layer of molecules with wetting responsibility based on the well-known simple surface chemistry. With targets in different concentrations, the wettability of the surface modified with responsive molecules would produce different changes. The responsive surfaces would change the capillary force of the vertical capillary tube, and result in different column heights. Like a thermometer, H+ and phenol have been quantified visually based on the height of the liquid inside the capillary tube. [ABSTRACT FROM AUTHOR]

Highly sensitive detection of 4-nitrophenol (4-NP), one of the most hazardous and toxic phenols, has been highly sought-after. In this study, we found that 4-NP could selectively quench the 410 nm emission of the dityrosine (diTyr) residues of BSA-protected gold nanoclusters (GNCs@BSA) rather than the conventional red emission of GNCs@BSA via the inner filter effect (IFE). This finding helped us to develop a label-free and separation-free ratiometric fluorescence method for sensing of 4-NP with red emissive GNCs as the endogenous reference for the first time. This ratiometric sensor exhibited rapid response to 4-NP within 1 min. The photoluminescence (PL) intensity ratio of the 410 nm emission of the diTyr residues to the 630 nm emission of the GNCs (F410/F630) showed a linear relationship with 4-NP concentration in the range of 50 to 5000 nM (R2 = 0.991) with a limit of detection (LOD) (S/N = 3) of 13.8 nM (1.9 ng mL−1), remarkably lower than the concentration limit released by the US Environmental Protection Agency (EPA) for drinking water (60 ng mL−1). Also, the ratiometric sensor showed selectivity for 4-NP over other eight common phenol derivatives. Furthermore, the ratiometric sensor was applied to analyze the trace 4-NP spiked in the tap and river water samples and the satisfied results were acquired, showing promising potential of the ratiometric sensor for practical applications. [ABSTRACT FROM AUTHOR]

One of the major challenges in heterogeneous catalysis is how to suppress the aggregation of thermodynamically unstable noble metal nanoparticles (NPs) and simultaneously maintain their high accessibility. Here we report the fabrication of integrated functional nanostructures consisting of a dendritic porous silica yolk with many small noble metal NPs and a protective mesoporous silica shell (MSS) with perpendicularly aligned pore channels and tunable shell thickness by using a well-controlled interfacial engineering strategy. Three-dimensional (3D) dendrimer-like superstructures with many permeable center-radial large pore channels and a highly accessible internal surface area, named dendritic porous silica spheres (DPSSs), serve as unique yolks not only because of their capability to accommodate high density ultrafine Au or Pt NPs, but also their functionality to act as robust physical barriers to separate and confine the aforementioned loaded NPs, which result in slowing down their aggregation at high temperatures due to Ostwald ripening. These integrated hierarchical structures also ensure good stability under weak basic and acidic conditions. Due to their superior structural properties, the DPSSs@noble metal NPs@MSS yolk–shell structures exhibit excellent catalytic performance in p-nitrophenol reduction, epoxidation reaction and CO oxidation. The favorable stability and high catalytic performance of these yolk–shell structures make the developed design strategy very useful for the fabrication of novel highly active and stable catalysts. [ABSTRACT FROM AUTHOR]

5-Carboxyfluorescein is verified to possess intrinsic peroxidase-like catalytic activity and can serve as a robust artificial peroxidase for the biomimetic synthesis of polyaniline nanoplatelets under harsh conditions. Our work discloses the potential of using this small molecule as a peroxidase surrogate for the biomimetic synthesis of nanostructured polymers. [ABSTRACT FROM AUTHOR]