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Herein, an enzyme- and label-free electrochemical aptasensor was developed for the amplified detection of protein (mucin 1, MUC1 as tested model) by utilizing autocatalytic and catabolic Mg2+-ligation DNAzyme as robust biocatalyst. The MUC1-affinity aptamer sequence is encoded in DNA hairpin 1 (HP1). The combined product of HP1 with MUC1 triggers the formation of active Mg2+-dependent DNAzyme in the presence of sequence-specific ssDNA (S1) and hairpin 2 (HP2) that especially consists of S1 and the other ssDNA (S2). When introducing Mg2+, HP2 as the substrate strand of this DNAzyme is cleaved at Mg2+-recognizable site, releasing S1 to repeatedly activate the autonomous replication and catabolism of new DNAzyme units. As a result, the multiple liberated S2 was further incubated in the modified electrode surface to unfold C-rich hairpin 3 (HP3) at neutral pH. While the formed duplex with negative charges is dehybridized due to the configuration switch of unfolded HP3 into positively charged i-motifs at decreased pH, leading to enhanced electrostatic attraction to redox pairs [Fe(CN)6]3−/4− and accelerated electron transfer in the electrode surface. Thus, the Faraday impedance (Ret) significantly decreased with MUC1-responsive variations for the electrochemical quantification of MUC1 in the range of 10 fg·mL−1 to 10 ng·mL−1, achieving high sensitivity down to 3.33 fg·mL−1, excellent specificity, reproducibility and stability. This strategy has proven to be promising application in actual biological samples.

Specific DNA sequence-templated silver nanoclusters (AgNCs) are extremely promising fluorescent emitters in biosensing and bioanalysis. Here, based on the targeted antibody-responsive fluorescent quenching of AgNCs harbored in a unique DNA-based nanoassembly, we propose a specific, sensitive and one-step immunoassay of bivalent anti-digoxigenin (Dig) antibody (antiDA) as a model analyte. For proof-of-concept, this functional nanoassembly (CS1/RS/CS2) consists of a reporter strand tethering Ag-nucleable template (RS) and two capture strands (CS1 and CS2) labeled with hapten Dig, in which two tethered Dig haptens are closely positioned, and brightly emissive AgNCs can be accommodated and stabilized in the unpaired Ag-nucleable scaffold to produce significant fluorescent emission (CS1/RS/CS2-AgNCs). In the presence of antiDA, the specific conjugation of antiDA with two Dig haptens results in the conformation stretch of CS1/RS/CS2, and simultaneously the harbored AgNCs are destabilized to aggregate each other into larger non-fluorescent silver nanoparticles (AgNPs). The remarkable decreasing of AgNCs fluorescence emission is linearly proportional to the antiDA concentration with a high sensitivity down to 4.5 pM. With this regulatory antibody-dependent signal off scheme, the advantageous rapidness and simplification would be attractive and promising for highly specific detection of diverse bivalent antibodies or small molecules.

The design, fabrication and characterization of a large displacement thermal actuator with a cascaded V-beam amplification for MEMS safety-and-arming (SA) devices are presented. The device is comprised of two V-shape electrothermal actuators, a cascaded V-beam amplification and two mechanical sliders. Compared with conventional lever amplifications, the vertical anti-acceleration stiffness of V-beam amplifications is much larger, which can meet the need of high-acceleration weapons. The special design of two symmetric mechanical sliders can double the displacement to ensure the MEMS SA device in armed state. The whole device is fabricated on a SOI wafer and fabrication process is introduced. Under an applied voltage of 15 V, the displacement of the device is 231.78 μm with consuming power of 5.10 W and response time of 16 ms. The chip size of the actuator is about 4 mm × 5 mm × 0.5 mm. The proposed actuator possesses outstanding performance in miniaturization, low cost and easy integration with other parts of MEMS SA devices.

In this work, a sensitive electrochemical aptasensor for thrombin (TB) based on synergetic catalysis of enzyme and porous Au@Pd core-shell nanostructure has been constructed. With the advantages of large surface area and outstanding catalytic performance, porous Au@Pd core-shell nanostructures were firstly employed as the nanocarrier for the immobilization of electroactive toluidine blue (Tb), hemin/G-quadruplex formed by intercalating hemin into the TB aptamer (TBA) and glucose oxidase (GOx). As a certain amount of glucose was added into the detection cell, GOx rapidly catalyzed the oxidation of glucose, coupling with the local generation of H2O2 in the presence of dissolved O2. Then, porous Au@Pd nanoparticles and hemin/G-quadruplex as the peroxidase mimics efficiently catalyzed the reduction of H2O2, amplifying the electrochemical signal and improving the sensitivity. Finally, a detection limit of 0.037pM for TB was achieved. The excellent performance of the aptasensor indicated its promising prospect as a valuable tool in simple and cost-effective TB detection in clinical application.

In this work, a label-free electrochemical aptasensor for sensitive detection of thrombin was fabricated and characterized. This aptasensor was based on the direct electron transfer of hemin and hemin functionalized reduced graphene oxide hybrid nanosheets (hemin@rGO) as the signal probe. Hemin@rGO with intrinsic peroxidase-like activity could catalyze the reaction of the peroxidase substrate because of the catalytic ability of hemin attached on the graphene surface through π–π interactions. The greatly enhanced sensitivity of the as-prepared aptasensor for thrombin was based on an effective signal amplification strategy. Firstly, the synthesized hemin@rGO nanosheets not only provided a large conductive interface, but also exhibited excellent redox activity with avoidance of an extra electroactive mediator. Secondly, the electrodeposition of Pt nanoparticles (PtNPs) on the resultant electrode surface effectively promoted the electron transfer and amplified the electrochemical response. Thirdly, further enhanced sensitivity was achieved by the outstanding catalytic performance of the horseradish peroxidase as the blocking reagent. On the basis of such a signal amplification strategy, the direct and facile electrochemical aptasensor showed superior electrocatalytic efficiency toward H2O2, and sensitively responded to 0.45 pM thrombin with a linear calibration range from 1 pM to 50 nM. So, the proposed detecting platform for thrombin could be promising for clinical analysis and assays.

In the present study, with the aggregated advantages of graphene and molybdenum disulfide (MoS2), we prepared poly(diallyldimethylammonium chloride)-graphene/molybdenum disulfide (PDDA-G-MoS2) nanocomposites with flower-like structure, large surface area and excellent conductivity. Furthermore, an advanced sandwich-type electrochemical assay for sensitive detection of thrombin (TB) was fabricated using palladium nanoparticles decorated PDDA-G-MoS2 (PdNPs/PDDA-G-MoS2) as nanocarriers, which were functionalized by hemin/G-quadruplex, glucose oxidase (GOD), and toluidine blue (Tb) as redox probes. The signal amplification strategy was achieved as follows: Firstly, the immobilized GOD could effectively catalyze the oxidation of glucose to gluconolactone, coupling with the reduction of the dissolved oxygen to H2O2. Then, both PdNPs and hemin/G-quadruplex acting as hydrogen peroxide (HRP)-mimicking enzyme could further catalyze the reduction of H2O2, resulting in significant electrochemical signal amplification. So the proposed aptasensor showed high sensitivity with a wide dynamic linear range of 0.0001 to 40 nM and a relatively low detection limit of 0.062 pM for TB determination. The strategy showed huge potential of application in protein detection and disease diagnosis.

Highly sensitive detection of carcinoembryonic antigen (CEA) is very important in clinical diagnosis and treatment assessment of cancers. In this work, we proposed a sensitive and selective electrochemical aptasensor for CEA detection using dendritic Pt@Au nanowires (Pt@AuNWs) as nanocarriers and electrocatalysts. With many advantages such as large specific surface area, good conductivity, excellent electrocatalytic activity and high stability, dendritic Pt@AuNWs were first employed as nanocarriers for immobilizing abundant thiol-terminated CEA aptamer 2 (CEAapt2) and redox-active toluidine blue (Tb), resulting in the formation of AuNWs–CEAapt2–Tb bioconjugate. In the presence of CEA, the proposed bioconjugate was captured onto the electrode surface through “sandwich” tactics. The electrochemical response was then triggered and further enhanced due to the favorable catalysis capacity of dendritic Pt@AuNWs with peroxidase mimic activity for the reduction of H2O2 added into the electrolytic cell, from which an improved sensitivity benefited and was successfully achieved. Under the optimal experimental conditions, the proposed aptasensor exhibited a linear response to CEA in the range of 0.001 ng mL−1 to 80 ng mL−1 and the limit of detection (LOD) is 0.31 pg mL−1. Moreover, the aptasensor exhibited good selectivity, stability and reproducibility, which indicated its potential applications in clinical diagnostics.

WO3−x nanomaterials have been demonstrated to be one kind of efficient near-infrared (NIR) laser-driven photothermal nanoagents, but their photothermal stability is still unsatisfied. In addition, a 980 nm laser is usually used as NIR light source, but it has an overheating effect due to optical absorption of water and biological specimens. To address these problems, we have prepared PEGylated Cs-doped WO3 (CsxWO3) nanorods by a solvothermal synthesis—PEGylation two-step route. CsxWO3 nanorods have diameters of ∼11 nm and lengths of ∼50 nm, and they exhibit increased absorption in the NIR region (700–1100 nm). With PEGylated CsxWO3 nanorods as the photothermal nanoagent, we compare the overheating and penetration effects of 915 and 980 nm lasers as NIR light sources. Compared with the 980 nm laser, the 915 nm laser provides drastically less overheating of water, and higher penetration ability of water/skin due to quite low water absorption. Importantly, under the irradiation of a 915 nm laser, CsxWO3 nanorods exhibit excellent photothermal conversion performance with high stability. Furthermore, by the photothermal effect of PEGylated CsxWO3 nanorods, in vivo cancer cells can be efficiently destroyed under the irradiation of a 915 nm laser. Therefore, PEGylated CsxWO3 nanorods can be used as a promising efficient and stable NIR-laser-driven photothermal agent against in vivo cancer cells.

In this work, a ‘signal on-off’ electrochemical peptide biosensor was developed for the determination of matrix metalloproteinase 2 (MMP-2) on the basis of target induced cleavage of a specific peptide. The prepared single-stranded DNA–porous platinum nanoparticles–peptide (S1–pPtNPs–P1) bioconjugates were employed as nanoprobes, where the specific peptide (P1, biotin–Gly–Pro–Leu–Gly–Val–Arg–Gly–Lys–Gly–Gly–Cys) was used as a cleavage-sensing element, offering the capability of ‘on-off’ electrochemical signalling for the target MMP-2. As for the construction of the biosensor, S1–pPtNPs–P1 was immobilized on the electrode surface through the conjunction of biotin–streptavidin. Then, hybridization chain reaction (HCR) was triggered to embed the electroactive thionine (Thi). The pPtNPs could effectively catalyze the decomposition of added H2O2, resulting in the electrochemical signal of Thi being enhanced significantly (‘signal on’ state). Upon sensing cleavage with MMP-2, pPtNPs and eletroactive Thi left the electrode surface, leading to an observable decrease in the electrochemical signal of Thi (‘signal off’ state). Compared with other methods of detecting MMP-2, the proposed ‘signal on-off’ electrochemical peptide biosensor exhibited an improved sensitivity with a detection limit of 0.32 pg mL−1 and wide linear range from 1 pg mL−1 to 10 ng mL−1.

Large-scale integration of traditional optical waveguide and electronic crystal devices cannot be realized because of optical diffraction. However, this restriction has been lifted by surface plasmon technology by providing the possibility of restraining and manipulating the light energy at the nano scale. In this study, the surface plasmon waveguide device of glass–lithium niobate–gold–lithium niobate has been designed. The structure consists of four layers: the first layer is glass, the third layer is periodic grating, and next to the grating is a symmetrical structure of lithium niobate. The grating thickness, LiNbO3 thickness, and Au grating width are used for modal analysis of the waveguide structure. Then, the test range of each parameter is adjusted in accordance with the simulation results to determine the optimal geometric parameters. Results show that the transmission loss is as low as 0.0004–0.0017 cm−1 and the normalized mode area is always less than 0.053 when the thickness range of lithium niobate is from 380 to 400 nm. Meanwhile, the optimum geometric parameters of the structure are obtained using comprehensive analysis of the simulation. The normalized field area is 0.0334 and the propagation loss is 0.0004 cm−1 when the Au thickness is 150 nm, the LiNbO3 thickness is 389 nm, and the grating width is 42 nm. In this condition, the waveguide can obtain deep subwavelength mode limiting capacity while reaching the minimum propagation. The structure can fully achieve the deep subwavelength constraints for the light field and exhibits excellent waveguide characteristics.

Metal nanoclusters (NCs) as a new type of electrochemiluminescence (ECL) nanomaterials have attracted great attention, but their applications are limited due to relatively low luminescent efficiency and a complex preparation process. Herein, an ultrasensitive ECL biosensor for the detection of Cyclin-D1 (CCND1) was designed by utilizing in situ electrogenerated silver nanoclusters (AgNCs) as ECL emitters and Fe3O4–CeO2 nanocomposites as a coreaction accelerator. The ECL luminous efficiency of AgNCs on the electrode could be significantly enhanced with the use of the Fe3O4–CeO2 for accelerating the reduction of S2O82– to generate the strong oxidizing intermediate radical SO4•–. As a result, the assay for CCND1 detection achieved excellent sensitivity with a linear range from 50 fg/mL to 50 ng/mL and limit of detection down to 28 fg/mL. Impressively, the efficiency of Traditional Chinese Medicines (TCM), sophorae, toward MCF-7 cells was successfully investigated due to the overexpression of CCND1 in relatio...

In this work, a simple and sensitive electrochemical aptasensor for protein (thrombin - TB used as the model) was developed by using cubic Cu

Plasmon lasers can support ultrasmall mode confinement and ultrafast dynamics with device feature sizes below the diffraction limit. At present in the single visible light frequency, the optical gain method of constraint SPP on metal nanowires structure reported less. We design the gold nanowire array structure, consisting of PMMA and R6G dye molecules as gain, by 488 nm pump in the middle of the nanowires position for wide range of light, use symmetry broken overcome that momentum does not match the photonic and SPP energy conversion. Theoretical analysis shows that dyes provide coherent optical feedback, resulting in nanowires face will observe laser properties of surface plasmons. Feature analysis: the incident light and pump joint strength is greater than the sum of strength which is the incident light, pump respectively. Under the effect of dye molecules gain effective, length of SPP transmission can increase 1 µm. The results achieved in a single optical frequency of stimulated radiation, application of dye optical gain can achieve continuous gain effect. This is for the future development of plasma amplifier and the wavelength laser. Keywords: SPP, Stimulated radiation, Gold nanowires array, Dye molecules

Lasers are nowadays widely used in industry, in hospitals and in many devices that we have at home. Random laser development is challenging given its high threshold and low integration. Surface plasmon polariton (SPP) can improve random laser characteristics because of its ability to control diffraction. In this study, we establish a random laser structural model with silicon-based parcel GaN nanowires. The GaN nanowire gain and enhanced surface plasmon increase population inversion level. Our laser model is based on random particle scattering feedback mechanism, nanowire use, and surface plasmon enhancement effect, which causes stochastic laser emergence. Analysis shows that the SPP mode and nanowire waveguides coupled in the dielectric layer of low refractive index can store light energy like a capacitor under low refractive index clearance. The waveguide mode field area and limiting factors show that the modeled laser can achieve sub-wavelength constraints of the output light field. We also investigate emergent laser performance for a more limited light field capacity and lower threshold. Keywords: Random laser, Surface plasmon polariton, Feedback mechanism, Low threshold, Subwavelength constraints

For the first time, a sandwich-type electrochemical method was proposed for ultrasensitive thrombin (TB) detection based on direct electrochemistry of highly loaded hemoglobin spheres-encapsulated platinum nanoparticles (PtNPs@Hb) as labels and electrocatalysts. The prepared PtNPs@Hb not only exhibited good biocompatibility, excellent electrocatalytic activity, but also presented redox activity of Hb. Thus, it was employed for the fabrication of aptasensor without any extraneous redox mediators, leading to a simple preparation process for the aptasensor. The high loading of Hb spheres as redox mediators could enhance the electrochemical signal. Importantly, the synergetic electrocatalytic behavior of Hb and PtNPs toward H2O2 reduction greatly amplified the electrochemical signal, resulting in the high sensitivity of aptasensor. Consequently, under optimal conditions, the designed aptasensor exhibited a lower detection limit of 0.05 pM and wide dynamic linear range from 0.15 pM to 40 nM for TB detection. Additionally, the proposed mediator-free and signal-amplified electrochemical aptasensor showed great potential in portable and cost-effective TB sensing devices.

In this work, a sensitive electrochemical aptasensor for the detection of thrombin (TB) is developed and demonstrated based on the co-catalysis of hemin/G-quadruplex, platinum nanoparticles (PtNPs) and flower-like MnO2 nanosphere functionalized multi-walled carbon nanotubes (MWCNT-MnO2).

In the present study, a sensitive electrochemical aptasensor based on exonuclease-catalyzed target recycling and enzyme-catalysis was developed for thrombin (TB) detection. Firstly, the alcohol dehydrogenase (ADH) was abundantly embedded in the 3-(mercaptopropyl)trimethoxysilane (MPTS) sol with a 3-D network that exhibited tunable porosity and high thermal stability. ADH, as an alcohol oxidase, catalyzed the conversation of alcohol into acetaldehyde coupling with the production of NADH in the presence of NAD + . Then the immobilized gold nanoparticles (AuNPs) could electrocatalyze the oxidation of NADH, finally promoting the redox reaction of the electroactive material methylene blue (MB) labeled on the hybrid double strand DNA (dsDNA). Furthermore, when the mixture of TB and RecJ f exonuclease was introduced, TB combined with the thrombin aptamer II (TBA II) and the aptamer–TB complex was formed. And then, the RecJ f exonuclease selectively degraded the TBA II from 5′→3′, releasing the target TB into the solution. The free TB was reused to combine with other TBA II to accomplish the target recycling and realize the electrochemical signal amplification. In this way, excellent sensitivity of the aptasensor was obtained. The thrombin aptasensor achieved a detection limit of 1.7 pM (defined as S/N=3) with a linear range from 5 pM to 100 nM. In addition, the proposed aptasensor had good stability and sensitivity, and would become a promising choice for the protein diagnostics in clinical analysis.

Photoluminescence electrospun fibers were prepared from poly(aryl ether)s solutions. The porosity and wrinkle fibers could be observed by scanning electron microscopy (SEM). The effect of solution properties on fiber surface morphologies was studied. Meanwhile, the rough fiber surfaces could make the electrospun membranes possess water repellency. The contact angles of electrospun membranes for water were around 140°. The emission spectra of these membranes indicated that the fibers exhibited multi-color including sapphire blue, olive green and rose red. It could provide a proposal for improving flexible optoelectronic devices based on electrospun membranes of conjugated polymers.

In this report, gold nanoparticle–graphene nanohybrids (Au–GR) and 3-amino-5-mercapto-1,2,4-triazole-functionalized multiwall carbon nanotubes (MWCNT–SH) were synthesized. And a novel hybrid material MWCNT–SH@Au–GR was obtained by the interaction between gold nanoparticles of two dimensional (2D) Au–GR and SH groups of 1D MWCNT–SH. Due to the synergistic effects between MWCNT–SH and Au–GR and excellent film forming ability of MWCNT–SH@Au–GR, the obtained MWCNT–SH@Au–GR was used as a modifier to fabricate a chemically modified electrode for the simultaneous determination of hydroquinone (HQ), catechol (CC), resorcinol (RC) and nitrite (NO2−). Scanning electron microscopy (SEM) was employed to characterize the morphology of MWCNT–SH@Au–GR. The electrochemical behavior of the sensor was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. Results showed that it was feasible to simultaneously measure HQ, CC, RC and NO2−. The linear response ranges for HQ, CC, RC and NO2− were 54.5–1250.5 μM, 11.0–126.0 μM, 43.5–778.5 μM and 86.0–7500.0 μM and the detection limits (S/N = 3) were 4.17 μM, 1.00 μM, 7.80 μM and 23.5 μM, respectively.

Herein, a strategy was put forward for sensitive label-free electrochemical immunosensor by using silver–graphene oxide (Ag–GO) as redox probe. Initially, a simple, soft reaction conditions and efficient route was designed to in situ reduce silver nanoparticles (AgNPs) onto graphene oxide (GO) by glucose as reducing agent. The obtained nanocomposite gave a pair of well-defined redox peaks with the advantages of good biocompatibility and chemical stability. Furthermore, the GO provided large surface area for assembly of abundant AgNPs with redox activity, which potentially paved sensitive way for immunodetection. Thus, the Ag–GO nanocomposites were used as redox probe to fabricate a sensitive label-free immunosensor for α-1-fetoprotein (AFP). In addition, gold nanoparticles (AuNPs) for immobilization of antibody (anti-AFP) could amplify the electrochemical signal and further enhance the sensitivity of the immunosensor due to its excellent conductivity and large surface area. Under the optimal condition, the anodic peak current linearly responded to the logarithm of AFP concentration in a wide range from 0.01 to 100 ng mL −1 with a low limit of detection of 3 pg mL −1 (S/N = 3). The designed immunosensor displayed the advantages of simple preparation, high sensitivity, good selectivity and satisfactory stability.

In this work, a sensitive electrochemical biosensing to Pb2+ was proposed based on the high specificity of DNAzymes to Pb2+. The response signal was efficiently amplified by the catalytic hairpin assembly induced by strand replacement reaction and the formation of dendritic structure DNA (DSDNA) by layer-by-layer assembly. Firstly, in the presence of Pb2+, the substrate strand (S1) of the Pb2+-specific DNAzymes was specifically cleaved by Pb2+. Secondly, one of the two fragments (rS1) introduced into the electrode surface was hybridized with a hairpin DNA (H1) and further replaced by another hairpin DNA (H2) by the hybridization reaction of H1 with H2. The released rS1 then induced the next hybridization with H1. After repeated cycles, the catalytic recycling assembly of H2 with H1 was completed. Thirdly, two bioconjugates of Pt@Pd nanocages (Pt@PdNCs) labeled with DNA S3/S4 and electroactive toluidine blue (Tb) (Tb-S3-Pt@PdNCs and Tb-S4-Pt@PdNCs) were captured onto the resultant electrode surface through the hybridization of S3 and H2, S3 and S4, resulting in the formation of DSDNA triggered by layer-by-layer assembly. This formed DSDNA greatly facilitated the immobilization of manganese(III) meso-tetrakis (4-N-methylpyridiniumyl)-porphyrin (MnTMPyP) as mimicking enzyme. Under the synergistic catalysis of Pt@PdNCs and MnTMPyP to H2O2 reduction, the effective signal amplification of the developed Pb2+ biosensor was achieved. As a result, the sensitive detection of the proposed electrochemical strategy for Pb2+ was greatly improved in the range of 0.1pM-200nM with a detection limit of 0.033pM.

We present a direct visual-inertial system that can track camera motions and map the environment. This method aligns input images directly based on the intensity of pixels and minimizes the photometric error, instead of using key features detected in the images. IMU measurements provide additional constraints to suppress the scale drift induced by the visual odometry. The depth information for each pixel can be computed either from the inverse depth estimation or from stereo images. Experiments using an existing dataset shows that the performance of our method is comparable to that of a latest reported method.

We reported on the synthesis and application of ionophore–gold nanoparticle conjugates in Ag + graphene paste electrode. Ionophore was a novel graphene oxide nanosheets (NGO) covalently grafted 2-thiophenecarboxylic (TPC) hybrid material. The hybrid material NGO–TPC decorated with gold nanoparticles was used as both a receptor and an ion-to-electron transducer to fabricate Ag + graphene paste electrode. The developed electrode was highly selective to Ag + over other tested cations and exhibited an excellent Nernstian slope of 59.3 mV dec −1 ranging from 8.4×10 −7 to 1.0×10 − M with a detection limit of 6.3×10 −7 M. Moreover, it also showed a fast response time and a long lifetime. Importantly, the new method of immobilizing ligands on NGO nanosheets to construct electrode successfully solved the universal problem of the electrode components loss from ion-selective electrode.

Decomposition of CO2 over reduced MFe2O4 (M = Ni, Co, Cu, Zn) was studied by H2–TPR, H2–TG, and CO2–TG. XRD Rietveld analysis was used for determining phase composition and crystallite size of reduced and oxidized samples. The results indicate that spinel CoFe2O4 and CuFe2O4 are reduced to metals by H2, while ZnFe2O4 and NiFe2O4 only partly reduced at 350 °C. The CoFe2O4 spinel ferrite shows the best activity in decomposing CO2 and the ZnFe2O4 shows the best recovery ability in the process of redox.

A highly selective PVC membrane electrode for Al3+ based on salicylaldehyde salicyloyl hydrazone as a neutral carrier has been prepared and studied. The sensor exhibits a good response for Al3+ over a linear range of 9.0 × 10-6 to 1.0 × 10-1 mol/L, with a Nernstian slope of 20.0 ± 0.2 mV/decade and detection limit of 7.0 × 10-6 mol/L. Selectivity coefficients determined by the method of separate solution indicate high selectivity for Al3+. The response mechanism was discussed in view of UV-Vis spectroscopy technique and the A.C. impedance technique. It was used as an indicator electrode in potentiometric titration of Al3+ with EDTA and in the determination of Al3+ in real samples. The electrode has a relatively fast response time, long life time and satisfactory stability.

The complexes of hydroxycitronellal ( o -aminobenzoic acid) copper(II) (Cu(II)-HXAB) and salicylaldehyde ( o -aminobenzoic acid) copper(II) (Cu(II)-SHAB) were used as neutral carriers in PVC-based membrane ion-selective electrodes. The electrode based on Cu(II)-HXAB exhibited near-Nernstian potential response to thiocyanate (SCN − ) in a linear range of 1.0 × 10 − 6 to 1.0 × 10 − 1 M with a detection limit of 8.5 × 10 − 7 M and a slope of − 57.3 mV/decade in 0.01 M phosphate buffer solution (pH 5.0). The electrode exhibited high selectivity to SCN − over other tested anions with an anti-Hofmeister selectivity sequence. The selectivity behavior might be discussed in terms of UV–Vis spectrum and infrared spectrum. The transfer process of thiocyanate across the membrane interface was investigated by making use of the AC impedance technique. The electrode containing Cu(II)-HXAB could be applied to thiocyanate analysis in waste water with satisfactory results.

The effects of phenanthrene (Phe) on hepatosomatic index (HSI) and hepatic enzymatic activities in hybrid tilapia (Oreochromis niloticus female x O. aureus male) were investigated via the static freshwater exposure at dosage of 50, 100, and 400 microg/L for 4-14 d. Compared with the control group, HSI was significantly decreased (P < 0.05) at 400 microg/L at day 14. Increased enzymatic activities (P < 0.05) were observed for catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) at either 100 or 400 microg/L at day 8 and 14, as well as for CAT at 50 microg/L at day 14, except for GPx at 400 microg/L at day 8. Ethoxyresorufin O-deethylase (EROD) activity was significantly increased (P < 0.05) at all dosage at day 4 as well as at 50 microg/L at day 8, but significantly decreased at either 100 or 400 microg/L at day 14 (P < 0.05). Glutathione-S-transferase (GST) activity was not affected. The results suggest that CAT, GPx, SOD and EROD, as well as HSI in tilapia may be used as the biomarkers or indexes for evaluating or monitoring the pollution of polycyclic aromatic hydrocarbons (PAHs) such as Phe.

Selectivity properties were established for salicylate-selective electrodes prepared by incorporating 2,9,16,23-copper(II)-tetranitrophthalocyanine (Cu(II)TNPc) and 2,9,16,23-copper(II)-tetraaminophthalocyanine (Cu(II)TAPc) into plasticized poly(vinyl chloride) (PVC) membranes. The effect of nature of plasticizer, concentrations of ionophore and anionic and cationic additives on the potential response of the electrode was investigated. The PVC membrane electrode based on Cu(II)TNPc exhibited preferential selectivity for salicylate (Sal−) over other tested anions. The best potential response characteristics of a wide working concentration range 1.0×10−1–9.0×10−7 mol·L−1 and a limit of detection of 7.2×10−7 mol·L−1 with a slope of (−59.8±0.5) mV/decade were observed for the membrane containing (w/w) 3.0% Cu(II)TNPc, 67.0% o-NPOE, 29.5% PVC, and 0.5% NaTPB. The proposed electrode with good stability and fast response could be used over a pH range of 3.0–7.0. And it was successfully applied to the determination of salicylate in actual samples with satisfactory results.

Cellulose acetate/nano-SiO2 composites were prepared and spun into fibers. Their morphology and tensile properties were investigated by scanning electron microscopy, specific surface area analysis by BET and static mechanical analysis. The results showed that the composite fibers had an optimal filtration effect on the tar and nicotine in cigarette smoke. Compared with conventional cellulose acetate fibers, the composite ones had greater specific surface area, and the reduction in tar and nicotine in the smoke after filtration with the composite fibers was 44% and 35%.

A novel solvent polymeric membrane electrode based on bis(1,3,4-thiadiazole) complexes of Hg(II) is described which has excellent selectivity and sensitivity toward iodide ion. The electrode, containing 1,4-bis(5-methyl-1,3,4-thiadiazole-2-yl-thio)butanemercury(II) [Hg(II)BMTB(NO3)4], has a Nernstian potentiometric response from 2.0 x 10(-8) to 2.0 x 10(-2) mol L(-1) with a detection limit of 8.0 x 10(-9) mol L(-1) and a slope of -59.0+/-0.5 mV/decade in 0.01 mol L(-1) phosphate buffer solution (pH 3.0, 20 degrees C). The selectivity sequence observed is iodidebromidethiocyanatenitritenitratechlorideperchlorateacetatesulfate. The selectivity behavior is discussed in terms of the UV-Vis spectrum, and the process of transfer of iodide across the membrane interface is investigated by use of the AC impedance technique. The electrode was successfully applied to the determination of iodide in Jialing River and Spring in Jinyun Mountains, with satisfactory results.

A sensitive and selective electrochemical aptasensor for thrombin detection was constructed based on hemin/G-quadruplex as the signal label and Fe3O4-Au nanocomposites with glucose oxidase (GOx-) and peroxide-mimicking enzyme activity as the signal enhancers. Due to their large surface area and good biocompatibility, Fe3O4-Au nanocomposites were employed to immobilize electroactive hemin/G-quadruplex, which was formed by the conjugation between a single-stranded guanine-rich nucleic acid and hemin. Based on the GOx-mimicking enzyme activity, Au nanoparticles on the surface of the Fe3O4-Au nanocomposites effectively catalyzed the oxidization of glucose in the presence of dissolved O2, accompanied by the production of H2O2. Both the Fe3O4 cores of Fe3O4-Au nanocomposites and hemin/G-quadruplex with H2O2-mimicking enzyme activity could catalyze the reduction of the generated H2O2, which promoted the electron transfer of hemin and amplified the electrochemical signal. The proposed electrochemical aptasensor had a wide dynamic linear range of 0.1 pM to 20 nM with a lower detection limit of 0.013 pM, which provided a promising method for a sensitive assay for the detection of proteins in electrochemical aptasensors.

In this work, a pseudo triple-enzyme cascade amplified electrochemical aptasensor based on hemin/G-quadruplex as signal label for thrombin (TB) was constructed and the amplified electrochemical signal was achieved by the corporate catalysis of alcohol dehydrogenase-graphene sheets (ADH-GSs) bionanocomposite and hemin/G-quadruplex, which simultaneously acted as NADH oxidase and HRP-mimicking DNAzyme. Through “sandwich” reaction, hemin/G-quadruplex labeled gold nanoparticles-ADH-GSs bionanocomposite (AuNPs-ADH-GSs) was captured on electrode surface and thus obtained the electrochemical signal. After the addition of ethanol into the electrolytic cell, ADH availably catalyzed the oxidation of ethanol with the reduction of NAD+ to NADH. Then, hemin/G-quadruplex as NADH oxidase catalyzed the oxidization of NADH, accompanying with the production of H2O2. Simultaneously, hemin/G-quadruplex as HRP-mimicking DNAzyme catalyzed the reduction of the generated H2O2. Such a catalysis strategy greatly promoted the electron transfer of hemin and resulted in the specific enhancement of electrochemical signal. The proposed TB aptasensor achieved a linear range of 1 pM–50 nM with a detection limit of 0.3 pM (defined as S/N=3). In addition, it showed satisfying stability and reproducibility, good specificity and sensitivity, indicating promising application for the detection of various proteins in clinical analysis.

Two key issues in active measurement are veracity and low injection traffic sent by measurement tool. The Spatio-Temporal Available Bandwidth (STAB) can obtain accurate available bandwidth on end-to-end network paths when available bandwidth is relative high. But this method may not run well when the bottleneck capacity or available bandwidth of a path is low. This paper proposes an improved active measurement algorithm based on STAB to obtain more accurate available bandwidth and reduce sent traffic under the condition that the available bandwidth or bottleneck capacity is low. Experiments show that the improved algorithm can greatly provide high veracity and reduce the measurement traffic when the available or bottleneck capacity is low.

Wireless ad hoc networks are very important in modern communication fields, in which routing protocols have been a hot research. AODV protocol has an important role in ad hoc networks. However, AODV uses flooding to find routes, and let the route from which receives the first RREP be the best routing, which means that the shortest time is the best. This mechanism is a reactive routing with expensive cost of time, and it does not have adaptive capacity to the network environment. In this paper, the solution of combining AODV with reinforcement learning is designed to make the improved AODV (which is called QAODV (Q-routing of AODV)) be adaptive to network environment. The node can reduce the frequency of finding routes by multi-path approach by QAODV. The simulation results show that latency and packet loss rate (PLR) of the improved routing protocol is significantly improved.

The effects of phenanthrene (Phe) on hepatosomatic index (HSI) and hepatic enzymatic activities in hybrid tilapia (Oreochromis niloticus female x O. aureus male) were investigated via the static freshwater exposure at dosage of 50, 100, and 400 microg/L for 4-14 d. Compared with the control group, HSI was significantly decreased (P0.05) at 400 microg/L at day 14. Increased enzymatic activities (P0.05) were observed for catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) at either 100 or 400 microg/L at day 8 and 14, as well as for CAT at 50 microg/L at day 14, except for GPx at 400 microg/L at day 8. Ethoxyresorufin O-deethylase (EROD) activity was significantly increased (P0.05) at all dosage at day 4 as well as at 50 microg/L at day 8, but significantly decreased at either 100 or 400 microg/L at day 14 (P0.05). Glutathione-S-transferase (GST) activity was not affected. The results suggest that CAT, GPx, SOD and EROD, as well as HSI in tilapia may be used as the biomarkers or indexes for evaluating or monitoring the pollution of polycyclic aromatic hydrocarbons (PAHs) such as Phe.

In this paper, a new PVC-based liquid-membrane anion-selective electrode based on a copper(II) of N,N'-bis(salicylidene)-1,2-bis(p-aminophenoxy)ethane tetradentate complex (Cu(II)BBAP) is described, which displays a preferential potentiometric response to iodide ion at pH 2.0 and an anti-Hofmeister selectivity sequence: I- >SCN > ClO 4 - > NO 2 > H 2 PO 4 - > NO 3 - > SO 4 2- > Br > Cl - . The electrode exhibits a near-Nemstian potential linear range of 8.2 x 10 -7 - 1.0 x 10 -1 M with a detection limit of 5.3 x 10 -7 M and a slope of -58.8 mV per decade. The A.C. impedance technique and the UV/Vis spectroscopy technique were used to analyze the response mechanism. The electrode could be applied to determine iodide in medicine analysis, and the obtained results were fairly satisfactory.

A novel thiocyanate (SCN−)-selective PVC membrane electrode based on a zinc-phthalocyanine (ZnPc) complex as neutral carrier is described. The membrane electrode containing ZnPc with 5.1% (w/w) ionophore, 29.2% (w/w) PVC, and 65.7% (w/w) 2-nitrophenyl octyl ether (o-NPOE) as plasticizer displayed an anti-Hofmeister selectivity sequence \({\text{(SCN}}^ - > {\text{Sal}}^ - > {\text{I}}^ - > {\text{ClO}}_{\text{4}} ^ - > {\text{Br}}^ - > {\text{Cl}}^ - > \operatorname{NO} _3 ^ - > {\text{NO}}_{\text{2}} ^ - > {\text{H}}_{\text{2}} {\text{PO}}_{\text{4}} ^ - > {\text{SO}}_{\text{4}} ^{2 - } )\), and exhibited near-Nernstian potential response to thiocyanate ranging from about 1.0×10−1 to 1.0×10−6 mol L−1 with a detection limit of 7.5×10−7 mol L−1 and a slope of 58.1±0.5 mV per decade in pH 3.0 phosphate buffer solution at 25 °C. This preferential response is believed to be associated with the unique coordination between the central metal of the carrier and thiocyanate.

A new highly selective thiocyanate electrode based on N,N′-bis-(furaldehyde)-1,2-phenylenediamine-dipicolyl copper(II) complex [Cu(II)-BFPD] as neutral carrier is described. The electrode has an anti-Hofmeister selectivity sequence: SCN−>I−>Sal−>ClO4 −>Br−>NO2 −>Cl−>NO3 −>SO4 2−>SO3 2−>H2PO4 − and a near-Nernstian potential linear range for thiocyanate from 1.0×10−1 to 5.0×10−6 mol L−1 with a detection limit 2.0×10−6 mol L−1 and a slope of 57.5 mV decade−1 in pH 5.0 of phosphate buffer solution at 20 °C. The response mechanism is discussed on the basis of results from A.C. impedance measurement and UV spectroscopy. The anti-Hofmeister behavior of the electrode results from a direct interaction between the central metal and the analyte ion and a steric effect associated with the structure of the carrier. The electrode has the advantages of simplicity, fast response, fair stability and reproducibility, and low detection limit. The selectivity of electrodes based on [Cu(II)-BFPD] exceeds that of classical anion-sensitive membrane electrodes based on ion exchangers such as lipophilic quaternary ammonium or phosphonium salts. Application of the electrode for determination of thiocyanate in waste water samples from a laboratory and a gas factory, and in human urine samples, is reported. The results obtained were fair agreement with the results obtained by HPLC.

Near-infrared (NIR) laser-induced photothermal ablation (PTA) therapy has great potential to revolutionize conventional therapeutic approaches for cancers, and a prerequisite is to obtain biocompatible and efficient photothermal agents. Herein, we have developed hydrophilic W18O49 nanowires with average lengths of about 800 nm (abbreviated as W18O49-800 NWs) as an efficient photothermal agent, which are prepared by the solvothermal synthesis—simultaneous PEGylation/exfoliation/breaking two-step route. These W18O49-800 NWs exhibit stronger NIR photoabsorption than short nanowires with average lengths of about 50 nm (abbreviated as W18O49-50 NWs) that are prepared via a solvothermal one-step route. Under irradiation of 980 nm with a safe intensity of 0.72 W cm−2, the aqueous dispersion of W18O49-800 NWs (1.0 mg mL−1) exhibits the temperature elevation by 35.2 °C in 5 min; which is a 37.5% increase compared to that (by 25.6 °C) from W18O49-50 NWs (1.0 mg mL−1). More importantly, under 980 nm laser irradiation (0.72 W cm−2) for 10 min, in vivo cancer cells can be efficiently ablated by the photothermal effects of W18O49-800 NWs. Therefore, these W18O49-800 NWs can be used as a more efficient and promising photothermal nanoagent for the ablation of cancer cells in vivo.

Wireless nanobiodevices (such as nanorobots) have great potential to revolutionize the diagnosis and therapeutic system for human health, but their applications have been limited by difficulties in fabricating such nanobiodevices, and one of the difficulties is to obtain an in vivo energy source as their biopower component. To address this problem, we have developed a kind of 980 nm laser-driven photovoltaic cell (980LD-PVC) by introducing a NaYF4:Yb,Er nanophosphor layer in conventional dye-sensitized solar cells, and its performance has been optimized by improving the up-conversion luminescence intensity of NaYF4:Yb,Er nanophosphors and adopting a succinonitrile-based gel electrolyte. Under the direct irradiation of a 980 nm laser with an illumination area of 2 × 8 mm2 and a safe intensity of 720 mW cm−2 that is slightly lower than the conservative limit (726 mW cm−2) for human skin exposure, 980LD-PVC without a liquid component exhibits a maximum output power of 44.5 μW and an overall 980 nm laser-to-electrical energy conversion efficiency of 0.039%. In particular, after being covered with chicken skin (thickness: 1 mm) as a model of biological tissue, 980LD-PVC still possesses a maximum output power of 22.2 μW and an overall conversion efficiency of 0.019%, which is still excellent enough to satisfy the power requirements of in vivo nanorobots (at least 1 μW) and cardiac pacemakers (about 10 μW). This research paves the way for the development of novel electrical sources to power wireless nanobiodevices and many other biodevices implanted under the human skin.