Engineering Interconnected Nanofluidic Channel in a Hydrogel Supernetwork toward K+ Ion Accelerating Transport and Efficient Sensing.

Ion transportation via the mixed mechanisms of hydrogels underpins ultrafast biological signal transmission in nature, and its application to the rapid and sensitive sensing detection of human specific ions is of great interest for the field of medical science. However, current research efforts are still unable to achieve transmission results that are comparable to those of bioelectric signals. Herein, 3D interconnected nanochannels based on poly(pyrrole-co-dopamine)/poly(vinyl alcohol) (P(Py-co-DA)/PVA) supernetwork conductive hydrogels are designed and fabricated as stimuli-responsive structures for K+ ions. Distinct from conventional configurations, which exhibit rapid electron transfer and permeability to biosubstrates, interconnected nanofluidic nanochannels collaborated with the P(Py-co-DA) conductive polymer in the supernetwork conductive hydrogel significantly improve conductivity (88.3 mS/cm), ion transport time (0.1 s), and ion sensitivity (74.6 mV/dec). The faster ion response time is attributed to the synergism of excellent conductivity originating from the P(Py-co-DA) polymer and the electronic effect in the interconnected nanofluidic channels. Furthermore, the supernetwork conductive hydrogel demonstrates K+ ion selectivity relative to other cations in biofluids such as Na+, Mg2+, and Ca2+. The DFT calculation indicates that the small solvation energy and low chemical transfer resistance are the main reasons for the excellent K+ ion selectivity. Finite element analysis (FEA) simulations further support these experimental results. Consequently, the P(Py-co-DA)/PVA supernetwork conductive hydrogels enriched with the 3D interconnected nanofluidic channels developed in this work possess excellent sensing of K+ ions. This strategy provides great insight into efficient ion sensing in traditional biomedical sensing that has not been explored by previous researchers.

IL-13 facilitates ferroptotic death in asthmatic epithelial cells via SOCS1-mediated ubiquitinated degradation of SLC7A11.

Th2-high asthma is characterized by elevated levels of type 2 cytokines, such as interleukin 13 (IL-13), and its prevalence has been increasing worldwide. Ferroptosis, a recently discovered type of programmed cell death, is involved in the pathological process of Th2-high asthma; however, the underlying mechanisms remain incompletely understood. In this study, we demonstrated that the serum level of malondialdehyde (MDA), an index of lipid peroxidation, positively correlated with IL-13 level and negatively correlated with the predicted forced expiratory volume in 1 s (FEV1%) in asthmatics. Furthermore, we showed that IL-13 facilitates ferroptosis by upregulating of suppressor of cytokine signaling 1 (SOCS1) through analyzing immortalized airway epithelial cells, human airway organoids, and the ovalbumin (OVA)-challenged asthma model. We identified that signal transducer and activator of transcription 6 (STAT6) promotes the transcription of SOCS1 upon IL-13 stimulation. Moreover, SOCS1, an E3 ubiquitin ligase, was found to bind to solute carrier family 7 member 11 (SLC7A11) and catalyze its ubiquitinated degradation, thereby promoting ferroptosis in airway epithelial cells. Last, we found that inhibiting SOCS1 can decrease ferroptosis in airway epithelial cells and alleviate airway hyperresponsiveness (AHR) in OVA-challenged wide-type mice, while SOCS1 overexpression exacerbated the above in OVA-challenged IL-13-knockout mice. Our findings reveal that the IL-13/STAT6/SOCS1/SLC7A11 pathway is a novel molecular mechanism for ferroptosis in Th2-high asthma, confirming that targeting ferroptosis in airway epithelial cells is a potential therapeutic strategy for Th2-high asthma.

Rapid runtime learning by curating small datasets of high-quality items obtained from memory.

We propose the "runtime learning" hypothesis which states that people quickly learn to perform unfamiliar tasks as the tasks arise by using task-relevant instances of concepts stored in memory during mental training. To make learning rapid, the hypothesis claims that only a few class instances are used, but these instances are especially valuable for training. The paper motivates the hypothesis by describing related ideas from the cognitive science and machine learning literatures. Using computer simulation, we show that deep neural networks (DNNs) can learn effectively from small, curated training sets, and that valuable training items tend to lie toward the centers of data item clusters in an abstract feature space. In a series of three behavioral experiments, we show that people can also learn effectively from small, curated training sets. Critically, we find that participant reaction times and fitted drift rates are best accounted for by the confidences of DNNs trained on small datasets of highly valuable items. We conclude that the runtime learning hypothesis is a novel conjecture about the relationship between learning and memory with the potential for explaining a wide variety of cognitive phenomena.

O-POSSUM and P-POSSUM as predictors of morbidity and mortality in older patients after hip fracture surgery: a meta-analysis.

BACKGROUND: The POSSUM model has been widely used to predict morbidity and mortality after general surgery. Modified versions known as O-POSSUM and P-POSSUM have been used extensively in orthopedic surgery, but their accuracy is unclear. This systematic review evaluated the predictive value of these models in older patients with hip fractures. METHODS: This study was performed and reported based on the "Preferred reporting items for systematic reviews and meta-analyses" guidelines. PubMed, Cochrane, EMBASE, and Web of Science were comprehensively searched for relevant studies, whose methodological quality was evaluated according to the "Methodological index for non-randomized studies" scale. Revman 5 was used to calculate weighted ratios of observed to expected morbidity or mortality. RESULTS: The meta-analysis included 10 studies, of which nine (2549 patients) assessed the ability of O-POSSUM to predict postoperative morbidity, nine (3649 patients) assessed the ability of O-POSSUM to predict postoperative mortality, and four (1794 patients) assessed the ability of P-POSSUM to predict postoperative mortality. The corresponding weighted ratios of observed to expected morbidity or mortality were 0.84 (95% CI 0.70-1.00), 0.68 (95% CI 0.49-0.95), and 0.61 (95% CI 0.16-2.38). CONCLUSIONS: While O-POSSUM shows reasonable accuracy in predicting postoperative morbidity in older patients with hip fractures, both P-POSSUM and O-POSSUM substantially overestimate postoperative mortality. The POSSUM model should be optimized further for this patient population.

Mesenchymal stem cell-derived extracellular vesicles, osteoimmunology and orthopedic diseases.

Mesenchymal stem cells (MSCs) play an important role in tissue healing and regenerative medicine due to their self-renewal and multi-directional differentiation properties. MSCs exert their therapeutic effects mainly via the paracrine pathway, which involves the secretion of extracellular vesicles (EVs). EVs have a high drug loading capacity and can transport various molecules, such as proteins, nucleic acids, and lipids, that can modify the course of diverse diseases. Due to their ability to maintain the therapeutic effects of their parent cells, MSC-derived EVs have emerged as a promising, safe cell-free treatment approach for tissue regeneration. With advances in inflammation research and emergence of the field of osteoimmunology, evidence has accumulated pointing to the role of inflammatory and osteoimmunological processes in the occurrence and progression of orthopedic diseases. Several studies have shown that MSC-derived EVs participate in bone regeneration and the pathophysiology of orthopedic diseases by regulating the inflammatory environment, enhancing angiogenesis, and promoting the differentiation and proliferation of osteoblasts and osteoclasts. In this review, we summarize recent advances in the application and functions of MSC-derived EVs as potential therapies against orthopedic diseases, including osteoarthritis, intervertebral disc degeneration, osteoporosis and osteonecrosis.

Associations between smoking and clinical outcomes after total hip and knee arthroplasty: A systematic review and meta-analysis.

Background: Smoking increases risk of several complications after total hip or knee arthroplasty (THA/TKA), so we systematically reviewed and meta-analyzed the literature to take into account all relevant evidence, particularly studies published since 2010. Methods: The PubMed, Ovid Embase, Web of Science, and EBSCOHost databases were searched and studies were selected and analyzed according to MOOSE recommendations. Methodological quality of included studies was assessed using the Newcastle-Ottawa Scale. Data were qualitatively synthesized or meta-analyzed using a random-effects model. Results: A total of 40 studies involving 3,037,683 cases were included. Qualitative analysis suggested that smoking is associated with worse patient-reported outcomes within one year after surgery, and meta-analysis showed that smoking significantly increased risk of the following outcomes: total complications (OR 1.41, 95% CI 1.01-1.98), wound complications (OR 1.77, 95% CI 1.50-2.10), prosthetic joint infection (OR 1.84, 95% CI 1.52-2.24), aseptic loosening (OR 1.62, 95% CI 1.12-2.34), revision (OR 2.12, 95% CI 1.46-3.08), cardiac arrest (OR 4.90, 95% CI 2.26-10.60), cerebrovascular accident (OR 2.22, 95% CI 1.01-4.85), pneumonia (OR 2.35, 95% CI 1.17-4.74), acute renal insufficiency (OR 2.01, 95% CI 1.48-2.73), sepsis (OR 4.35, 95% CI 1.35-14.00), inpatient mortality (OR 12.37, 95% CI 4.46-34.28), and persistent opioid consumption (OR 1.64, 95% CI 1.39-1.92). Conclusion: Smoking patients undergoing THA and TKA are at increased risk of numerous complications, inpatient mortality, persistent opioid consumption, and worse 1-year patient-reported outcomes. Pre-surgical protocols for these outcomes should give special consideration to smoking patients.

Chaotropic Polymer Additive with Ion Transport Tunnel Enable Dendrite-Free Zinc Battery.

Zn batteries are considered the new-generation candidate for large-scale energy storage systems, taking both safety and environmental problems into account. They are still restricted by unexpected dendrite/byproducts occurring on the Zn anodes. We hereby screen a powerful polymer type additive, hyaluronic acid (HA), to regulate the typical ZnSO4 electrolyte for obtaining dendrite-free Zn ion batteries. The intrinsically chaotropic property of the HA molecule can efficiently destruct the original hydrogen-bonds from H2O-H2O, thus restricting the common parasitic reactions derived from the large amount of active water molecules. Simultaneously, the abundant functional groups along the long chain from HA additives can construct an effective tunnel for transferring Zn2+ smoothly, enabling an obviously improved Zn ion transference number of 0.62. Owning to the above intriguing mechanism for regulating the solvation structure of electrolyte systems, the HA additives can greatly increase the cycling life of Zn-Zn symmetric cells to 2200 and 800 h under the conditions of 1 mA cm-2/1 mAh cm-2 and 5 mA cm-2/5 mAh cm-2, respectively. Modified performance for both Zn-Ti and Zn-MnO2 can all be realized by this valid additive, elucidating it can be potentially utilized in large-scale Zn based aqueous energy storage devices.

Circ_0088036 mediated progression and inflammation in fibroblast-like synoviocytes of rheumatoid arthritis by miR-1263/REL-activated NF-κB pathway.

BACKGROUND: Rheumatoid arthritis (RA) is a common joint disease with abnormal development of human fibroblast-like synoviocytes (HFLS). Circular RNAs (circRNAs) have essential regulation in the disease progression, and this study was to explore the regulatory mechanism of circ_0088036 in RA. METHODS: RNA expression analysis was performed through reverse transcription-quantitative polymerase chain reaction assay. Cell experiments were conducted by Cell Counting Kit-8 assay for cell viability, EdU (5-ethynyl-2'-deoxyuridine) assay for proliferation and flow cytometry for cell cycle or apoptosis. The protein detection was conducted using western blot. Enzyme-linked immunosorbent assay (ELISA) was used to examine the inflammatory cytokines. The binding identification was carried out through dual-luciferase reporter assay, RNA immunoprecipitation assay and pull-down assay. RESULTS: The level of circ_0088036 RNA was significantly upregulated in sera and in HFLS cells of RA patients. Targeted silencing of circ_0088036 restrained proliferation, cell cycle progression and inflammatory reaction through promoted the apoptosis of HFLS-RA cells via inhibiting the NF-κB pathway. The miR-1263 was identified as a target of circ_0088036. MiR-1263 was found to be down-regulated in sera and in HFLS cells of RA patients. The regulatory effects of circ_0088036 on HFLS-RA cells were attributed to inhibit the miR-1263 level. REL is a susceptibility locus for certain autoimmune diseases. MiR-1263 directly targeted REL, which was discovered to be elevated in sera and HFLS cells of RA patients, and circ_0088036 interacted with miR-1263 to affect REL expression. Functionally, overexpression of miR-1263 suppressed the development of HFLS-RA by blocking the NF-κB pathway, and this phenomenon was reversed by the upregulation of REL. CONCLUSION: These findings suggested that circ_0088036/miR-1263/REL/NF-κB pathway was involved in the functional development of HFLS-RA cells, indicating a novel molecular network in RA progression in vitro.

Hybrid 3D printed integrated microdevice for the determination of copper ions in human body fluids.

On-site screening of copper ions in body fluid plays a critical role in monitoring human health, especially in heavy pollution areas. In this study, we have developed a hybrid 3D printed integrated microdevice for the determination of copper ions in human body fluids. A fixed and low volume of sample was detected by using the integrated microdevice without any preprocessing. The hybrid channel enables sample uniform mixing and quantitative dilution with buffer solution by inducing the "horseshoe vortex" phenomenon. The electrolytic microcell based on the flow detection system shows a more effective copper ion reaction ratio and, as a result, a better sensitivity. The simulation of the finite element method (FEM) determined the relevant optimum parameters of the hybrid channel and the microcell. The design, fabrication, and detection procedure of the integrated microdevice are here illustrated. The microdevice presented superior detection properties towards copper ions. The calibration curves covered two linear ranges varying from 20 to 100 ppb and 100 to 400 ppb, respectively. The limit of detection was estimated to be 15 ppb (S/N = 3). The relative standard deviation of the peak current measurements was 2.26%. The designed microdevice was further applied to detect copper ions in practical samples (calf serum sample and synthetic human urine sample) using a standard addition method, and the average recovery was found to be 95-104%. The performance of copper ion detection with the integrated microdevice was consistent with that of the inductively coupled plasma mass spectrometry (ICP-MS) in the same practical samples, demonstrating significant practicality in the test of body fluidics. The portable integrated microdevice is an excellent choice for on-site detection and has a promising prospect in the point-of-care testing (POCT) applications.

A graphene-based electrochemical flow analysis device for simultaneous determination of dopamine, 5-hydroxytryptamine, and melatonin.

Developing an accurate, sensitive, and efficient portable device for simultaneous detection of disease-related biomolecules is an attractive challenge for point-of-care testing (POCT). In this work, we introduced a novel graphene-based electrochemical flow analysis device (GEFAD), which combined a 3D-printed flow cell with a three-electrode system based on a gold nanoparticle-modified graphene (AuNPs@Gr) working electrode to simultaneously detect depression-related biomolecules: dopamine (DA), 5-hydroxytrypserotonin (5-HT), and melatonin (MEL). Electrochemical studies showed that the GEFAD had high selectivity and sensitivity in the determination of DA, 5-HT, and MEL with their significant separation peaks. The linear ranges of DA, 5-HT, and MEL were respectively found to be 0.1-70 µM, 0.1-100 µM, and 0.1-150 µM, with the corresponding detection limits of 0.054 µM, 0.071 µM, and 0.087 µM (S/N = 3). In addition, the GEFAD presented a good anti-interference ability and satisfactory reproducibility, and can be used in real calf serum sample analysis. The introduced in-flow electrochemical detection device showed excellent repeatability, less sample consumption, and simple operation, which increases the possibility to implement POCT. This study also proposed a promising application prospect for the development of portable biomolecules detection devices.

Manipulating Interfacial Stability Via Absorption-Competition Mechanism for Long-Lifespan Zn Anode.

The stability of Zn anode in various Zn-based energy storage devices is the key problem to be solved. Herein, aromatic aldehyde additives are selected to modulate the interface reactions between the Zn anode and electrolyte. Through comprehensively considering electrochemical measurements, DFT calculations and FEA simulations, novel mechanisms of one kind of aromatic aldehyde, veratraldehyde in inhibiting Zn dendrite/by-products can be obtained. This additive prefers to absorb on the Zn surface than H2O molecules and Zn2+, while competes with hydrogen evolution reaction and Zn plating/stripping process via redox reactions, thus preventing the decomposition of active H2O near the interface and uncontrollable Zn dendrite growth via a synactic absorption-competition mechanism. As a result, Zn-Zn symmetric cells with the veratraldehyde additive realize an excellent cycling life of 3200 h under 1 mA cm-2/1 mAh cm-2 and over 800 h even under 5 mA cm-2/5 mAh cm-2. Moreover, Zn-Ti and Zn-MnO2 cells with the veratraldehyde additive both obtain elevated performance than that with pure ZnSO4 electrolyte. Finally, two more aromatic aldehyde additives are chosen to prove their universality in stabilizing Zn anodes.

Liquid-like Polymer Coating as a Promising Candidate for Reducing Electrode Contamination and Noise in Complex Biofluids.

Biosensors that can automatically and continuously track fluctuations in biomarker levels over time are essential for real-time sensing in biomedical and environmental applications. Although many electrochemical sensors have been developed to quickly and sensitively monitor biomarkers, their sensing stability in complex biofluids is disturbed by unavoidable nonspecific adhesion of proteins or bacteria. Recently, various substrate surface modification techniques have been developed to resist biofouling, yet functionalization of electrodes in sensors to be anti-biofouling is rarely achieved. Here, we report an integrated three-electrode system (ITES) modified with a "liquid-like" polydimethylsiloxane (PDMS) brush that can continuously and stably monitor reactive oxygen species (ROS) in complex fluids. Based on the slippery "liquid-like" coating, the modified ITES surface could prevent the adhesion of various liquids as well as the adhesion of proteins and bacteria. The "liquid-like" coating does not significantly affect the sensitivity of the electrode in detecting ROS, while the sensing performance could remain stable and free of bacterial attack even after 3 days of incubation with bacteria. In addition, the PDMS brush-modified ITES (PMITES) could continuously record ROS levels in bacterial-rich fluids with excellent stability over 24 h due to the reduced bacterial contamination on the electrode surface. This technique offers new opportunities for continuous and real-time monitoring of biomarkers that will facilitate the development of advanced sensors for biomedical and environmental applications.

A three-electrode integrated electrochemical platform based on nanoporous gold for the simultaneous determination of hydroquinone and catechol with high selectivity.

In this study, a novel three-electrode integrated electrochemical platform (TEIEP) has been designed and fabricated for the simultaneous detection of hydroquinone (HQ) and catechol (CC), in which nanoporous gold (NPG) served as the working electrode, and Pt particles and nanoporous Ag/AgCl served as the courter electrode and the reference electrode, respectively. Due to the remarkable catalytic activity of NPG, the TEIEP exhibits high selectivity and sensitivity towards HQ and CC determination with a distinct separation between the peaks for their coexistence. The oxidation peak current densities of HQ and CC were linear over the range of 0.2-100 µM with the detection limits of 0.083 µM (S/N = 3) for HQ and 0.119 µM (S/N = 3) for CC. Moreover, TEIEP has a satisfactory reproducibility and anti-interference ability, and can be used in real water sample analysis. This work undoubtedly provides a remarkable choice for catalytic materials and an integrated structure, and further a promising application prospect for developing novel sensors for on-site environmental monitoring.

Association of rs2862851 in TGFA Gene with Peripheral TGFA Levels and the Severity of Knee Osteoarthritis in the Han Chinese Population.

Background: Osteoarthritis (OA) is a complex joint disorder characterized by sclerosis of subchondral bone. The knee is one of the most commonly affected joints. Given that the genetic mechanisms underlying knee OA remain elusive, our study aims were to first confirm the association of the TGFA gene alleles with the risk of knee OA and, second, to evaluate the relationship between peripheral TGFA concentrations and knee OA in an independent Han Chinese population. Materials and Methods: We performed a case-control study consisting of 392 knee OA patients and 808 unrelated healthy controls. Single-marker-based association analyses and haplotype-based analyses using 3 single nucleotide polymorphisms (SNPs) were performed to confirm the association of TGFA gene alleles with the risk of knee OA. Furthermore, we used enzyme-linked immunosorbent assay (ELISA) kits to detect the peripheral blood TGFA concentrations in patients and healthy controls and then evaluated the relationships between the TGFA alleles and genotypes with serum TGFA levels. Results: We replicated the genetic association of the rs2862851 T allele with the risk of knee OA (p = 1.68 × 10-4, OR = 1.41). Moreover, we observed that the peripheral TGFA concentrations were higher in knee OA patients than in healthy controls (p = 8.15 × 10-13). The peripheral TGFA concentrations were significantly different among the various rs2862851 genotypes for both cases (p = 4.16 × 10-16) and controls (p = 7.24 × 10-19). The individuals with the TT genotype in both cases and controls, had the highest peripheral TGFA concentrations. Moreover, with the increase in knee OA grade, peripheral TGFA concentration also increased (p = 1.36 × 10-72). Conclusion: Our study confirmed the association of the TGFA gene with the risk of knee OA and identified a positive correlation between peripheral TGFA levels and the severity of knee OA in the Han Chinese population, providing clues for understanding the etiology of knee OA.

A Flexible Portable Glucose Sensor Based on Hierarchical Arrays of Au@Cu(OH)2 Nanograss.

Flexible physiological medical devices have gradually spread to the lives of people, especially the elderly. Here, a flexible integrated sensor based on Au nanoparticle modified copper hydroxide nanograss arrays on flexible carbon fiber cloth (Au@Cu(OH)2/CFC) is fabricated by a facile electrochemical method. The sensor possesses ultrahigh sensitivity of 7.35 mA mM-1 cm-2 in the linear concentration range of 0.10 to 3.30 mM and an ultralow detection limit down to 26.97 nM. The fantastic sensing properties can be ascribed to the collective effect of the superior electrochemical catalytic activity of nanograss arrays with dramatically enhanced electrochemically active surface area as well as mass transfer ability when modified with Au and intimate contact between the active material (Au@Cu(OH)2) and current collector (CFC), concurrently supplying good conductivity for electron/ion transport during glucose biosensing. Furthermore, the device also exhibits excellent anti-interference and stability for glucose detection. Owing to the distinguished performances, the novel sensor shows extreme reliability for practical glucose testing in human serum and juice samples. Significantly, these unique properties and the soft structure of silk fabric can provide a promising structure design for a flexible micro-device and a great potential material candidate of electrochemical glucose sensor.

A Flexible Microsupercapacitor with Integral Photocatalytic Fuel Cell for Self-Charging.

With the rapid advancement in different kinds of portable electronics, self-powered systems with small volume and high-performance characteristics have attracted great attention in recent years. It would be rather exciting if one integrated system can not only convert recyclable energy or waste to electricity but also store energy at the same time. Here, flexible all-in-one energy chips composed of urea-based photocatalytic fuel cells (PFCs) and asymmetric microsupercapacitors (AMSCs) are designed on the same plane for powering small portable electronics. The planar PFC consisting of TiO2 photoanode and Ag counter electrode, utilizing urea as fuel, can produce a stable energy output (highest power density of 3.04 µW cm-2 in 1 M urea solution under a UV intensity of 30 mW cm-2) while purify this wasted water simultaneously. Besides, the AMSC comprised of NiCoP@NiOOH positive electrode and zeolite imidazolide framework derived carbon (ZIF-C) negative electrode achieves a high areal capacitance of 54.7 mF cm-2 at 0.5 mA cm-2 and an excellent energy density of 13.9 µWh cm-2 at the power density of 270.5 µW cm-2. Its stability can be confirmed by 86% capacitance retention after 8000 electrochemical cycles and almost no decay after 500 bending cycles. Four PFCs and two AMSCs can be easily constructed into an energy chip and power small electronics. This eco-friendly and self-sustainable system has great potential in future portable electronics.

Thermal Characterization of Low-Dimensional Materials by Resistance Thermometers.

The design, fabrication, and use of a hotspot-producing and temperature-sensing resistance thermometer for evaluating the thermal properties of low-dimensional materials are described in this paper. The materials that are characterized include one-dimensional (1D) carbon nanotubes, and two-dimensional (2D) graphene and boron nitride films. The excellent thermal performance of these materials shows great potential for cooling electronic devices and systems such as in three-dimensional (3D) integrated chip-stacks, power amplifiers, and light-emitting diodes. The thermometers are designed to be serpentine-shaped platinum resistors serving both as hotspots and temperature sensors. By using these thermometers, the thermal performance of the abovementioned emerging low-dimensional materials was evaluated with high accuracy.

Hierarchical bi-continuous Pt decorated nanoporous Au-Sn alloy on carbon fiber paper for ascorbic acid, dopamine and uric acid simultaneous sensing.

In this work, Pt nanoparticles modified nanoporous AuSn(Pt@NP-AuSn) alloy on Ni buffered flexible carbon fiber paper (CFP) is fabricated by a simple replacement reaction in which NP-AuSn is fabricated by controllable dealloy of electrodeposited Au-Sn alloy films. The as prepared Pt@NP-AuSn/Ni/CFP possesses hierarchical pore structure, high specific surface area and excellent catalytic activity. Due to the bi-functions of both the large surface area of nanoporous metal and macroporous of carbon fiber paper facilitating mass transfer, the Pt@NP-AuSn/Ni/CFP shows high sensitivity of detecting ascorbic acid (AA), dopamine (DA) and uric acid (UA), with sensitivities of 0.14 µA µM-1 cm-2, 15.23 µA µM-1 cm-2, 0.28 µA µM-1 cm-2 under the concentration ranging from 200 to 2000 µM, 1-10 µM, and 25-800 µM for AA, DA and UA, respectively. Further, the Pt@NP-AuSn/Ni/CFP possesses long-term stability of sensing AA, DA and UA and presents great anti-interference towards a variety of common compounds in body fluid. All of these results manifest the Pt@NP-AuSn/Ni/CFP can be a promising candidate for the application of the electrochemical sensor for simultaneous detection of AA, DA and UA.

Alleviating concentration polarization: a micro three-electrode interdigitated glucose sensor based on nanoporous gold from a mild process.

Precisely detecting the concentration of glucose in the human body is an attractive way to prevent or diagnose diabetes. Compared with the traditional enzyme-based electrochemical glucose sensors, the non-enzymatic ones have gradually come to people's attention recently. By integrating three electrodes into one device, glucose sensors can achieve superior performance and are convenient to carry. Herein, a non-enzymatic three-electrode interdigitated glucose sensor (TEIDGS) based on nanoporous gold is designed and fabricated. To our best knowledge, it is the first time that interdigitated electrodes are combined in a single non-enzymatic glucose sensor device. Due to the advantage of the interdigitated structure and the smart design of the three-electrode circuit board, the TEIDGS can effectively reduce concentration polarization and achieve a high detective sensitivity for glucose of 1217 µA mM-1 cm-2 and 343 µA mM-1 cm-2 in the ranges of 0.001-0.590 mM and 0.59-7.00 mM, respectively. Moreover, a low detection limit of 390 nM can be reached. In addition, this TEIDGS possesses excellent selectivity for glucose among other interferents. Strikingly, after three weeks of operation, it can still retain a high detection performance. This work will certainly provide an efficient structure and proper catalytic material choice for future non-enzymatic glucose sensors.

Three-Dimensional Bi-Continuous Nanoporous Gold/Nickel Foam Supported MnO2 for High Performance Supercapacitors.

A three-dimensional bi-continuous nanoporous gold (NPG)/nickel foam is developed though the electrodeposition of a gold-tin alloy on Ni foam and subsequent chemical dealloying of tin. The newly-designed 3D metal structure is used to anchor MnO2 nanosheets for high-performance supercapacitors. The formed ternary composite electrodes exhibit significantly-enhanced capacitance performance, rate capability, and excellent cycling stability. A specific capacitance of 442 Fg-1 is achieved at a scan rate of 5 mV s-1 and a relatively high mass loading of 865 µg cm-2. After 2500 cycles, only a 1% decay is found at a scan rate of 50 mV s-1. A high power density of 3513 W kg-1 and an energy density of 25.73 Wh kg-1 are realized for potential energy storage devices. The results demonstrate that the NPG/nickel foam hybrid structure significantly improves the dispersibility of MnO2 and makes it promising for practical energy storage applications.