Formulating compatible non-flammable electrolyte for lithium-ion batteries with ethoxy (pentafluoro) cyclotriphosphazene.

Lithium (Li) ion batteries have played a great role in modern society as being extensively used in commercial electronic products, electric vehicles, and energy storage systems. However, battery safety issues have gained growing concerns as there might be thermal runaway, fire or even explosion under external abuse. To tackle these safety issues, developing non-flammable electrolytes is a promising strategy. However, the balance between the flame-retarding effect and the electrochemical performance of electrolytes remains a great challenge. Herein, we evaluate the function of ethoxy (pentafluoro) cyclotriphosphazene (PFPN) as an effective flame-retarding additive for lithium-ion batteries. The flammability of electrolytes is greatly suppressed with the introduction of a small amount of PFPN. Moreover, PFPN exhibited excellent compatibility with LiFePO4 (LFP) cathode and graphite (Gr) anode, the electrochemical performances of LFP|Li and Gr|Li half cells are virtually unaffected. Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) reveal the stable interphase between PFPN-containing electrolyte and LFP and Gr electrodes. Fourier transform infrared spectroscopy (FT-IR), Raman and nuclear magnetic resonance (NMR) spectra demonstrate the introduction of PFPN only exhibits negligible influence on the solvation structure of electrolyte. Benefiting from these merits of PFPN, the LFP|Gr cell shows desirable long-term cycling performance, which demonstrates great potential for practical application.

FastCAT: A framework for fast routing table calculation incorporating multiple protocols.

Currently, most network outages occur because of manual configuration errors. Therefore, it is essential to verify the correctness of network configurations before deployment. Computing the network control plane is a key technology for network configuration verification. We can verify the correctness of network configurations for fault tolerance by generating routing tables, as well as connectivity. However, existing routing table calculation tools have disadvantages such as lack of user-friendliness, limited expressiveness, and slower speed of routing table generation. In this paper, we present FastCAT, a framework for computing routing tables incorporating multiple protocols. FastCAT can simulate the interaction of multiple routing protocols and quickly generate routing tables based on configuration files and topology information. The key to FastCAT's performance is that FastCAT focuses only on the final stable state of the OSPF and IS-IS protocols, disregarding the transient states during protocol convergence. For RIPv2 and BGP, FastCAT computes the current protocol routing tables based on the protocol's previous state, retaining only the most recent protocol routing tables in the latest state. Experimental evaluations have shown that FastCAT generates routing tables more quickly and accurately than the state-of-the-art routing simulation tool, in a general network of around 200 routers.

High-Speed Path Probing Method for Large-Scale Network.

In large-scale network topology discovery, due to the complex network structure and dynamic change characteristics, it is always the focus of network topology measurement to obtain as many network paths as possible in a short time. In this paper, we propose a large-scale network path probing approach in order to solve the problems of low probing efficiency and high probing redundancy commonly found in current research. By improving the packet delivery order and the update strategy of time-to-live field values, we redesigned and implemented an efficient large-scale network path probing tool. The experimental results show that the method-derived tool can complete path probing for a sample of 12 million/24 network address segments worldwide within 1 hour, which greatly improves the efficiency of network path probing. Meanwhile, compared to existing methods, the proposed method can reduce the number of packets sent by about 10% with the same number of network addresses found, which effectively reduces probing redundancy and alleviates the network load.

Signal-On Electrochemical Detection for Drug-Resistant Hepatitis B Virus Mutants through Three-Way Junction Transduction and Exonuclease III-Assisted Catalyzed Hairpin Assembly.

The present detection method for hepatitis B virus (HBV) drug-resistant mutation has a high misdiagnosis rate and usually needs to meet stringent requirements for technology and equipment, leading to complex and time-consuming manipulation and drawback of high costs. Herein, with the purpose of developing cost-effective, highly efficient, and handy diagnosis for HBV drug-resistant mutants, we propose an electrochemical signal-on strategy through the three-way junction (3WJ) transduction and exonuclease III (Exo III)-assisted catalyzed hairpin assembly (CHA). To achieve single-copy gene detection, loop-mediated nucleic acid isothermal amplification (LAMP), one of the highly promising and compatible techniques to revolutionize point-of-care genetic detection, is first adopted for amplification. The rtN236T mutation, an error encoded by codon 236 of the reverse transcriptase region of HBV DNA, was employed as the model gene target. Under the optimized conditions, it allows end-point transduction from HBV drug-resistant mutants-genomic information to electrochemical signals with ultrahigh sensitivity, specificity, and signal-to-noise ratio, showing the lowest detection concentration down to 2 copies/µL. Such a method provides a possibly new principle for ideal in vitro diagnosis, supporting the construction of a clinic HBV diagnosis platform with high accuracy and generalization. Moreover, it is not restricted by specific nucleic acid sequences but can be applied to the detection of various disease genes, laying the foundation for multiple detection.

A non-symbiotic novel species, Rhizobium populisoli sp. nov., isolated from rhizosphere soil of Populus popularis.

Strain XQZ8T, isolated from the rhizosphere soil of a Populus popularis plant in China, was characterized using a polyphasic taxonomic approach. Cells were Gram-negative, aerobic, non-spore-forming, and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XQZ8T was related to members of the genus Rhizobium and had the highest 16S rRNA gene sequence similarity to Rhizobium smilacinae PTYR-5T (96.6%). The average nucleotide identity and digital DNA-DNA hybridization value between strain XQZ8T and R. smilacinae PTYR-5T were 77.5% and 21.4%, respectively. TYGS whole-genome-based taxonomic and multi-locus sequence analyses of three concatenated housekeeping genes (atpD-recA-glnII) further indicated that strain XQZ8T was a new member of the genus Rhizobium. The major cellular fatty acids included summed feature 8 (C18:1 ω7c/C18:1 ω6c), summed feature 2 (C12:0 aldehyde/unknown 10.928), C16:0, and C19:0 cyclo ω8c. The major respiratory quinones were Q-9 and Q-10. The polar lipids were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, an unidentified glycophospholipid, and three unidentified lipids. The genomic DNA G + C content of the strain was 60.1 mol%. Based on the phylogenetic, phenotypic, and genotypic characteristics, strain XQZ8T represents a novel species of the genus Rhizobium, for which the name Rhizobium populisoli sp. nov. is proposed. The type strain is XQZ8T (= JCM 34442T = GDMCC 1.2201T).

Vacancy Engineering to Regulate Photocatalytic Activity of Polymer Photosensitizers for Amplifying Photodynamic Therapy against Hypoxic Tumors.

Polymer photosensitizers (PPSs) with the distinctive properties of good light-harvesting capability, high photostability, and excellent tumor retention effects have aroused great research interest in photodynamic therapy (PDT). However, their potential translation into clinic was often constrained by the hypoxic nature of tumor microenvironment, the aggregation-caused reduced production of reactive oxygen species (ROS), and the tedious procedure of manufacture. As a powerful and versatile strategy, vacancy engineering possesses the unique capability to effectively improve the photogenerated electron efficiency of nanomaterials for high-performance O2 and ROS production. Herein, by introducing vacancy engineering into the design of PPSs for PDT for the first time, we synthesized a novel PPS of Au-decorated polythionine (PTh) nanoconstructs (PTh@Au NCs) with the unique integrated features of distinguished O2 self-evolving function and highly efficient ROS generation for achieving the greatly enhanced PDT efficacy toward hypoxic tumor both in vitro and in vivo. The incorporation of Au into PTh leads to the special PTh-Au heterostructure-induced sulfur vacancies in PTh@Au NCs, which results in an efficient electron-hole separation performance and also plays a key role in a long lifetime of free electrons and holes. Accordingly, an ∼2- to 3-fold ROS generation and an ∼1.5-fold increase of O2 self-supply than the pure PTh nanoparticles (NPs) were obtained even under hypoxic conditions upon exposure to 650 nm light. By combining such superior ROS generation and O2 self-supply performances with the outstanding cellular internalization and tumor accumulation capacities, an advanced antitumor effect with the achievement of almost complete hypoxic tumor elimination in vivo or 88% cell destruction in vitro was acquired by the PTh@Au NCs. In addition, the distinctive facile one-step redox strategy for PTh@Au NCs synthesis compared to the reported PPSs for PDT also makes it beneficial for potential practical application. The first introduction of vacancy engineering concept into PPSs in the field of PDT proposed in this work offers a new strategy for the development and design highly efficient PPSs for PDT applications.

Tumor microenvironment-responsive nanozymes achieve photothermal-enhanced multiple catalysis against tumor hypoxia.

Reactive oxygen species (ROS)-mediated antitumor modalities that induced oxidative damage of cancer cells have recently acquired increasing attention on account of their noninvasiveness, low systemic toxicity, and high specificity. However, their clinical efficacy was often constrained by complex and various tumor microenvironment (TME), especially hypoxia characteristic and antioxidation effect of glutathione (GSH). Herein, we constructed a multinanozyme system based on hyaluronic acid (HA)-stabilized CuMnOx nanoparticles (CMOH) loaded with indocyanine green (ICG) with high-efficient ROS generation, O2 self-evolving function, GSH depletion ability and hyperthermia effect for achieving hypoxic tumor therapy. The CMOH nanozymes exhibited peroxidase-like and oxidase-like activities, which could efficiently catalyze H2O2 or O2 to generate hydroxyl radicals (•OH) or superoxide radicals (•O2-) in acidic tumor microenvironment (TME), elevating oxidative stress of tumor. Indocyanine green (ICG) was further loaded into HA-CuMnOx to form HA-CuMnOx@ICG nanocomposites (CMOI NCs), which can effectively generate singlet oxygen (1O2) and local hyperthermia under light irradiation. The hyperthermia generated by CMOI NCs further enhances the catalytic activities of nanozymes for ROS generation. Meanwhile, the CMOI with catalase-like activity could catalyze H2O2 into O2 for relieving tumor hypoxia and elevate O2-dependent ROS generation. Notably, CMOI can consume endogenous GSH, thereby impairing tumor antioxidant system and enhancing ROS-based therapy efficacy. After modified with HA, CMOI NCs with tumor targeting ability realized synergistic PTT-enhanced tumor oxidation therapy based on their multimodal properties. Thus, this work contributes to design high-performance therapeutic reagent to overcome the limitation of hypoxia and high antioxidant defense of tumor. STATEMENT OF SIGNIFICANCE: Reactive oxygen species (ROS)-mediated antitumor modalities were often constrained by complex and various tumor microenvironment (TME), especially hypoxia characteristic and antioxidation effect of glutathione (GSH). In this work, a multinanozyme system based on hyaluronic acid (HA)-stabilized CuMnOx nanoparticles (CMOH) loaded with indocyanine green (ICG) was designed to realize PTT-enhanced multiple catalysis tumor therapy. Although antitumor modalities based on multienzyme catalysis have been developed. Here, we highlighted the responsive catalysis of multienzyme system on tumor microenvironment (TME) and the promoting effect of photothermal effect on ROS production. Both in vitro and in vivo manifested that the enhanced anticancer efficacy of CMOI NCs due to their thermally amplified catalytic activity and TME regulation ability.

Fake and dishonest participant location scheme in secret image sharing.

A (k,n) threshold secret image sharing (SIS) scheme divides a secret image into n shadows. One can reconstruct the secret image only when holding k or more than k shadows but cannot know any information on the secret from fewer than k shadows. Based on this characteristic, SIS has been widely used in access control, information hiding, distributed storage and other areas. Verifiable SIS aims to prevent malicious behaviour by attackers through verifying the authenticity of shadows and previous works did not solve this problem well. Our contribution is that we proposed a verifiable SIS scheme which combined CRT-based SIS and (2,n+1) threshold visual secret sharing(VSS). Our scheme is applicable no matter whether there exists a third party dealer. And it is worth mentioning that when the dealer is involved, our scheme can not only detect fake participants, but also locate dishonest participants. In general, loose screening criterion and efficient encoding and decoding rate of CRT-based SIS guarantee high-efficiency shadows generation and low recovery computation complexity. The uncertainty of the bits used for screening prevents malicious behavior by dishonest participants. In addition, our scheme has the advantages of lossless recovery, no pixel expansion and precise detection.

Sweet potato derived three-dimensional carbon aerogels with a hierarchical meso-macroporous and branching nanostructure for electroanalysis.

In this paper, sweet potatoes (Ipomoea batatas) are used as low-cost precursors to synthesize carbon aerogels with a hierarchical meso-macroporous and branching nanostructure (HMM-BNCA). An HMM-BNCA-modified glassy carbon electrode (GCE) (HMM-BNCA/GCE) exhibits high electrocatalytic activity for some electroactive biomolecules. For ascorbic acid (AA), the HMM-BNCA/GCE exhibits low oxidation peak potential and detection limit (-0.005 V and 0.45 µM, S/N = 3), high sensitivities (195.43 and 121.00 µA mM-1 cm-2) and wide linear ranges (10-1250 µM and 1250-4750 µM), which are superior to those obtained at the GCE and carbon nanotube (CNT)-modified GCE (CNT/GCE). The HMM-BNCA/GCE exhibits significant resistance to fouling and the interfering substances for the detection of AA. The successful and accurate detection of AA in real samples (such as vitamin C injections and vitamin C soft drinks) in this work demonstrates the feasibility and tremendous potential of HMM-BNCA/GCE for the analysis of AA in complex systems.

Thiourea-assistant growth of In2O3 porous pompon assembled from 2D nanosheets for enhanced ethanol sensing performance.

The flower-like porous In2O3 pompon assembled from two-dimensional (2D) nanosheets was synthesized through a simple thiourea-assistant hydrothermal method following the annealed process. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images manifest that the In2O3 pompon possesses a clear porous structure with a nanosheet thickness of about 37.5 nm. Further, we compare the performance of intermediate products (In2S3, In2S3/In2O3) and In2O3 nanostructures as ethanol detection gas sensors. The fabrication of In2O3-based sensors exhibits enhanced ethanol sensing performance than that of In2S3/In2O3-based and In2S3-based sensors, which is mainly attributed to more chemical oxygen and oxygen vacancies on the material surface. The In2O3-based sensors for ethanol detection revealed a wide linear range from 2 ppm to 100 ppm, meanwhile the corresponding detection limits (LOD) as low as ~0.4 ppm at 260 °C. And the In2O3-based sensors also exhibit superior repeatability and reliable selectivity. The simple fabrication strategy of 2D nanosheets-assembled flower-like In2O3 porous pompon may facilitate other ethanol gas sensors production and other 2D metal oxide semiconductor materials-based sensors preparation.

Oxygen vacancy-enhanced photothermal performance and reactive oxygen species generation for synergistic tumour therapy.

Vacancy engineering is a robust strategy to tune nanomaterials' electronic structures for physicochemical properties regulation. Here, we report and realize the first oxygen vacancy-enhanced photothermal and oxidation dual-induced synergistic tumour therapy using oxygen vacancies enriched MnO2@Au nanoconstructs as the therapeutic agent with a high photothermal effect, enhanced highly-toxic superoxide radical generation, good biocompatibility and tumour microenvironment regulation capacity. Our work opens up a new route for cancer nanotheranostics by regulating the electronic structure of nanomaterials resulting in enhanced efficacy.

Biomass derived worm-like nitrogen-doped-carbon framework for trace determination of toxic heavy metal lead (II).

The worm-like nitrogen-doped-carbon framework (WNCF) with abundant edge-plane-like defective sites (EDSs) was synthesized by using natural wax gourd (Benincasa hispida) as the main carbon precursor and milk yielded by Chinese Holstein cattle (Holstein Friesian) as the nitrogen precursor for the first time. The Nafion-dispersed WNCF (Nafion-WNCF) was employed to design a highly sensitive electrochemical sensor for the trace determination of toxic heavy metal lead (II) (Pb2+) by the differential pulse anodic stripping voltammetry (DPASV). Some key experimental factors including calcination temperature of WNCF, pH value of the buffer solution, deposition potential, deposition time and the concentration of bismuth (Bi3+) were optimized for the stripping analysis of Pb2+. Under the optimum experimental condition, Nafion-WNCF modified bismuth film glassy carbon electrode (Nafion-WNCF/BFGCE) exhibits a wide linear range from 0.5 µg L-1 to 100 µg L-1 and a low detection limit of 0.2 µg L-1 (S/N = 3) for detecting Pb2+. Especially, Nafion-WNCF/BFGCE was successfully applied to determine Pb2+ in tap water and lake water samples. All the results suggest that the WNCF can be considered as a green and low-cost nanomaterial for the precision detection of Pb2+ in real samples.

Ultrasensitive electrochemiluminescence biosensing platform for miRNA-21 and MUC1 detection based on dual catalytic hairpin assembly.

Multi-target detection has been widely applied for the sensitive measurement of cancer-related biomarkers; however, the design and application of single platforms for diverse target detection are still challenging. Herein, a robust and sensitive electrochemiluminescence (ECL) biosensing platform was constructed for the measurement of microRNA-21 (miRNA-21) and mucin 1 (MUC1) based on dual catalytic hairpin assembly (DCHA). The catalytic hairpin assembly (CHA) process (Cycle I) was initiated by the target miRNA-21 to introduce abundant CdS:Mn quantum dots (CdS:Mn QDs) on the electrode surface, leading to a considerable ECL response and the sensitive detection of miRNA-21 with a limit of detection as low as 11 aM. Subsequently, the second CHA process (Cycle II) was triggered by the MUC1-aptamer complex, which allowed copious amounts of Au nanoparticles (AuNPs) to approach the CdS:Mn QDs. A decreased ECL signal was obtained due to the ECL resonance energy transfer (ECL-RET) effect between the CdS:Mn QDs and AuNPs; meanwhile, MUC1 was sensitively detected with a limit of detection of 0.40 fg mL-1. This single sensing platform achieved dual cancer-related biomarker detection, which could provide a rational approach for future clinical analyse.

Green and low-cost synthesis of nitrogen-doped graphene-like mesoporous nanosheets from the biomass waste of okara for the amperometric detection of vitamin C in real samples.

In this work, the low-cost nitrogen-doped graphene-like mesoporous nanosheets (N-GMNs) was synthesized from the biomass waste of okara for the first time for the construction of a nonenzymatic amperometric vitamin C biosensor. The N-GMNs modified glassy carbon electrode (N-GMNs/GCE) shows much lower overpotential for the electrooxidation of vitamin C comparing to the traditional GCE as well as the GCE modified by carbon nanotubes (CNTs/GCE), indicating the promising of N-GMNs/GCE for the sensitive and selective nonenzymatic amperometric vitamin C biosensing. As a nonenzymatic amperometric biosensor for vitamin C, the N-GMNs/GCE shows a higher sensitivity (144.65 µA mM-1 cm-2), a wider linear range (10-5640 µmol L-1) and a lower detection limit (0.51 µmol L-1) than GCE, CNTs/GCE or some of recently reported nanomaterials-based electrochemical vitamin C biosensors. Especially, the vitamin C concentration in real samples of commercial beverage, vitamin C injection and commercial juice can be determined by the proposed N-GMNs/GCE with satisfied results. Therefore, the utilization of okara as the raw material for the synthesis of nanostructured carbon of N-GMNs is a green method to fabricate an advanced and low-cost electrode material for developing the nonenzymatic electrochemical biosensor for vitamin C detection.

Correction to: Synthesis of a three-dimensional interconnected carbon nanorod aerogel from wax gourd for amperometric sensing.

The published version of this article, unfortunately, contains error. The authors regret that one typo was present in the first author name "Cuxing Xu" when it should be "Cuixing Xu".

Low-cost and environment-friendly synthesis of carbon nanorods assembled hierarchical meso-macroporous carbons networks aerogels from natural apples for the electrochemical determination of ascorbic acid and hydrogen peroxide.

In this work, the low-cost carbon nanorods assembled hierarchical meso-macroporous carbons networks aerogels (CNs-HMCNAs) was environment-friendly synthesized from a cheap and abundant biomass of apples (Malus pumila Mill) for the first time. The biomass of apples derived CNs-HMCNAs exhibited the unique hierarchical meso-macroporous structure with large specific surface area and high density of edge defective sites. At the CNs-HMCNAs modified GCE (CNs-HMCNAs/GCE), the electron transfer between the glassy carbon electrode (GCE) and the ascorbic acid (AA) (or hydrogen peroxide (H2O2)) was effectively enhanced, and thus induced a low overvoltage for AA electrooxidation (or H2O2 electroreduction). As an electrochemical AA (or H2O2) sensor, the CNs-HMCNAs/GCE exhibited wider linear range, lower detection limit, higher sensitivity and stability than GCE and the carbon nanotubes modified GCE (CNTs/GCE). In particular, the CNs-HMCNAs/GCE showed great potential feasibility in the practical determination of AA (in AA injection, Vitamin C tablet and kiwi juice) or H2O2 (in human urine, milk and beer).

Amperometric sensing of ascorbic acid by using a glassy carbon electrode modified with mesoporous carbon nanorods.

Mesoporous carbon nanorods (MCNRs) were prepared from honey as the carbon source and by using crab (Brachyuran) shells as the hard template. The unique nanostructure of the MCNRs with their uniform mesoporous size, abundant defective sites and numerous oxygen-functional groups was characterized by nitrogen adsorption-desorption isotherms, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Cyclic voltammograms of a glassy carbon electrode (GCE) modified with MCNRs revel a higher peak current density and lower peak potential (-0.03 V vs. Ag/AgCl) for ascorbic acid (AA) electrooxidation compared to a conventional GCE and a carbon nanotube-modified GCE. Figures of merit for this sensor include (a) a wide linear range (10-2770 µM), (b) high electrochemical sensitivity (216.91 µA mM-1 cm-2) and (c) a low detection limit (2.3 µM). These compare favorably to the respective data for a CNT-modified GCE (50-2150 µM, 5.20 µA mM-1 cm-2 and 26.8 µM) and a plain GCE (100-2000 µM, 0.58 µA mM-1 cm-2 and 54.6 µM). The modified GCE was successfully applied to the determination of AA in (spiked) real samples including an injection, soft drinks and fresh lemon juice. Therefore, the new sensor can be considered as an affordable tool for electrochemical sensing of AA in real samples. Graphical abstract Mesoporous carbon nanorods (MCNRs) were prepared by using honey as the carbon source and crab shells as the hard template. The MCNRs modified a glassy carbon electrode (MCNRs/GCE) was used for the ascorbic acid (AA) detection by amperometry.

Synthesis of a three-dimensional interconnected carbon nanorod aerogel from wax gourd for amperometric sensing.

The authors describe a method for synthesis of a three-dimensional (3D) interconnected carbon nanorod aerogel (3D-ICNA) starting from wax gourd (Benincasa hispida) which is a low-cost biomass. The 3D-ICNA possesses unique 3D interconnected and porous nanostructure, with abundant edge-plane-like defective sites, a large specific surface area (823 m2 g-1) and a large pore volume (0.12 cm3 g-1). This makes the material attractive in terms of electrochemical sensing. To validate the feasibility, the voltammetric response towards ferricyanide, hydrogen peroxide (H2O2), acetaminophen, ascorbic acid (AA), dopamine, uric acid and epinephrine was investigated by using a glassy carbon electrode (GCE) modified with 3D-ICNA. The modified GCE shows higher electron-transfer capacity than a conventional GCE. In addition, as an electrochemical sensor for AA or H2O2, the electrode exhibits better analytical performance with lower detection limit [3.5 µM for AA or 0.68 µM for H2O2 based on 3σ/m criterion (where σ is the standard deviation of the blank and m is the slope of the calibration plot)], wider linear range and higher sensitivity (0.14, 0.11 and 0.080 µA µM-1 cm-2 for AA or 0.24 and 0.20 µA µM-1 cm-2 for H2O2) compared to a plain GCE or a carbon nanotube-modified GCE. The modified GCE exhibits a large potential for the amperometric determination of AA or H2O2 in real samples. Graphical abstract By employing the biomass of wax gourd (Benincasa hispida) as the precursor, a three-dimensional interconnected carbon nanorod aerogel was prepared. It is shown to be a viable material for the construction of an advanced electrochemical sensor for H2O2 and ascorbic acid.

Cost-effective synthesis of three-dimensional nitrogen-doped nanostructured carbons with hierarchical architectures from the biomass of sea-tangle for the amperometric determination of ascorbic acid.

In this work, the three-dimensional nitrogen-doped nanostructured carbons with hierarchical architectures (3D-NNCsHAs) with high density of defective sites, high surface area and pluralities of pore size distributions was prepared through the pyrolysis of sea-tangle (Laminaria japonica), an inexpensive, eco-friendly and abundant precursor. Benefitting from their structural uniqueness, a selective and sensitive ascorbic acid (AA) sensor based on 3D-NNCsHAs was developed. Compared to the glassy carbon electrode (GCE) and the carbon nanotubes modified GCE (CNTs/GCE), the 3D-NNCsHAs modified GCE (3D-NNCsHAs/GCE) presents higher performance towards the electrocatalysis and detection of AA, such as lower detection limit (1 µM), wider linear range (10-4410 µM) and lower electrooxidation peak potential (-0.02 V vs. Ag/AgCl). In addition, 3D-NNCsHAs/GCE also exhibits high anti-interference and anti-fouling abilities for AA detection. Particularly, the fabricated 3D-NNCsHAs/GCE is able to determine AA in real samples and the results acquired are satisfactory. Therefore, the 3D-NNCsHAs can be considered as a kind of novel electrode nanomaterial for the fabrication of selective and sensitive AA sensor for the extensive practical applications ranging from food analysis, to pharmaceutical industry and clinical test.

Electrochemical sensing platform based on kelp-derived hierarchical meso-macroporous carbons.

In this paper, kelp (Laminaria japonica), as a kind of abundant biomass, is used as the precursor for the preparation of kelp-derived hierarchical meso-macroporous carbons (K-dHMMCs) through the carbonization under nitrogen (N2) atmosphere at high temperature. The K-dHMMCs exhibits the unique structure with high specific surface area of 416.02 m2 g-1, large pore volume of 0.24 cm3 g-1, the hierarchical meso-macroporous size distribution centered at 2, 12 and 82 nm and high density of defective sites, enabling K-dHMMCs attractive for the electrocatalysis. Drop-casting K-dHMMCs on the glassy carbon (GC) surface allows the construction of K-dHMMCs based electrochemical sensing platform, which shows electrocatalytic activities towards many electroactive molecules, such as potassium ferricyanide, nicotinamide adenine dinucleotide (NADH), hydrogen peroxide (H2O2), dopamine (DA), uric acid (UA), ascorbic acid (AA), epinephrine (EP), l-tyrosine (Tyr) and acetaminophen (APAP). Especially, the K-dHMMCs modified GC (K-dHMMCs/GC) electrode exhibits higher sensitivity, wider linear range, and lower detection limit than both carbon nanotubes modified GC (CNTs/GC) and GC electrodes for H2O2 detection, which makes the K-dHMMCs/GC electrode to be able to determine the H2O2 levels in human urine sample and monitor the H2O2 released from human cancer cells. These results demonstrate that K-dHMMCs/GC possesses a great potential for conventional electrochemical sensing applications.