Anti Interference Research Articles

A dicyanisophorone based fluorescent probe for naked–eye recognition and near–infrared fluorescence detection of palladium

The eco–environmental toxicity of the rare metal palladium (Pd) has received extensive attention, thereby requiring simple and practical methods for detecting Pd. Herein, a new probe (HPD) based on dicyanoisophorone dye was designed and synthesized for the detection of Pd. HPD provides several advantages for tracking Pd, including near–infrared (NIR) emission (λex = 670 nm, λem = 700 nm), naked–eye recognition, and comprehensive detection of 0/2/4 valence Pd with good selectivity and anti–interference. The reaction–sensing mechanism of HPD for Pd was further studied using density functional theory calculations. HPD was demonstrated to be a promising tool for the detection of Pd in real water samples, as well as the imaging of Pd in living cells and animals.

Hydrothermal synthesis of ZnZrO2/chitosan (ZnZrO2/CS) nanocomposite for highly sensitive detection of glucose and hydrogen peroxide

In this work, pure ZnZrO2 and chitosan supported (ZnZrO2/CS) nanocomposite have been synthesized at low coast by hydrothermal method. FT-IR, Micro Raman, PXRD, HR-SEM-EDAX, HR-TEM, AFM, BET and XPS were used to analyze the structural and morphological properties of the fabricated nanocomposites. The fabricated ZnZrO2 and ZnZrO2/CS nanocomposites were measured for their electrocatalytic activity towards glucose and hydrogen peroxide determinations. The ZnZrO2/CS sensor exhibited wide detection range (5 μM to 5.85 mM), high sensitivity (6.78 μA mM−1 cm−2), LOD (2.31 μM), and long-term stability for glucose detection in alkaline solution. Also, as a multifunctional electrochemical sensor, ZnZrO2/CS sensor exhibits excellent sensing ability towards hydrogen peroxide, with a wide dynamic range (20 μM to 6.85 mM), a high sensitivity (2.22 μA mM−1 cm−2), and a LOD (2.08 μM) (S/N = 3). The electrochemical measurement shows that the ZnZrO2/CS sensor has excellent catalytic activity and a much LOD than ZnZrO2. The modified electrode showed excellent anti interference nature. Furthermore, this ZnZrO2/CS electrode was used to detection of glucose and H2O2 in human blood serum and HeLa cells respectively.

A Non–Enzymatic Electrochemical Sensor of Cu@Co–MOF Composite for Glucose Detection with High Sensitivity and Selectivity

A 3D cobalt metal–organic framework (Co–MOF), [Co3(BDC)3(DMU)2], was utilized to prepare Cu@Co–MOF composite in a deposition–reduction process. Cu@Co–MOF/GCE (GCE = glassy carbon electrode) electrode was prepared by “drop–coating” method. Cu@Co–MOF/GCE shows excellent electrocatalytic activity for Glu detection. The chronoamperometric response of Cu@Co–MOF/GCE to Glu concentration (CGlu) displays linear relationships in two CGlu sections with calculated sensitivities of 282.89 μA mM−1 cm−2 within 0.005–0.4 mM Glu and 113.15 μA mM−1 cm−2 within 0.4–1.8 mM Glu. The detection limit is calculated as 1.6 μM at S/N = 3. Cu@Co–MOF/GCE also exhibits a rapid current response, high anti–interference, stability, and repeatability to Glu detection. Cu@Co–MOF/GCE was applied to detect Glu in human serum and orange juice. All found CGlu are very close to those added CGlu with low RSDs and high recoveries. Cu@Co–MOF/GCE as a non–enzymatic electrochemical sensor of Glu has high sensitivity, selectivity, accuracy, and reliability.

A Multi − Site initiation reversible Addition − Fragmentation Chain − Transfer electrochemical cocaine sensing

In this study, we reported a novel amplification method based on thermally mediated surface − initiated reversible addition − fragmentation chain transfer (SI–RAFT) and host–guest chemistry for electrochemical analysis of cocaine. Firstly, the NH2–DNA probes were fixed on the surface of the indium tin oxide (ITO) electrode by addition reaction with 1,4–phenylenediisothiocyanate (PDITC). Then the NH2–DNA could specifically recognize target cocaine, and the Ferrocene–DNA (Fc–DNA) probes was connected to the ITO electrode also by specifically binding with cocaine. Next, β–CD–Br15 was fixed on the surface of the ITO by host–guest interaction between Fc and β–cyclodextrin (β–CD). Finally, ferrocenylmethyl methacrylates (FcMMA) were grown on the surface of ITO via SI–RAFT to form polymer, and then the obtained electrode was measured by square wave voltammetry (SWV). The intensity of signal and the logarithm of cocaine concentration has a good linear relationship in the range of 0.01 ng/mL to 1 µg/mL (R2 = 0.9963), and the detection limit can go down to 0.003 ng/mL (S/N = 3). Moreover, this strategy is appropriate for illegal drugs detection and possess good anti–interference ability for the detection of cocaine in serum samples.

A new naphthalimide-picolinohydrazide derived fluorescent “turn-on” probe for hypersensitive detection of Al3+ ions and applications of real water analysis and bio-imaging

The development of high-selective chemosensors for trace Al3+ detection in the ecosystem is crucially importance due to its detrimental effects. In this work, a simple Schiff-base fluorescent probe NPP derived from naphthalimide and picolinohydrazide was rationally designed and prepared for efficient detection of Al3+. NPP exhibited prominent sensing behaviors toward Al3+ with low detection limit (LOD) (39 nM), rapid response time (1 min), strong binding affinity (4.02 × 104), good anti–interference characteristics and visual detection. Binding ratio of NPP-Al3+ complex was determined to be 1:1 by Job’s plot analysis. In addition, the chelation mechanism of NPP with Al3+ ions was proposed and substantiated by the density functional theory (DFT) and time-dependent density functional theory (TD-DFT), IR spectrum and 1H NMR titration experiments. Furthermore, this “signal-on” probe NPP was efficiently utilized as a promising indicator for Al3+ detection in environmental and biological samples.

Switching the free radical based peroxydisulfate activation to the nonradical pathway by a chrome shaving–derived biochar for the efficient degradation of tetracycline

The nonradical pathway in peroxydisulfate (PDS) activation for refractory contaminant removal has attracted increasing attention due to its inherent advantages. Hence, a new bimetallic biochar (Cr–Fe/BC) was synthesized via pyrolysis by using chrome shaving and ferric sulfate as the raw materials. Results illustrated that tetracycline (TC) could been completely removed in a small amount of Cr–Fe/BC (0.03 g/L) and PDS (2 mM) within 60 min with a high mineralization rate (82%). Besides, the Cr–Fe/BC/PDS system exhibited a strong anti–interference capability for coexisting organics and inorganics in water. Based on the results of various spectroscopic evidences and DFT calculations, iron introduction successfully transformed the free radical degradation process that was dominated by sulfate radicals (SO4–) into the nonradical degradation process that was dominated by electron transfer. The tunning mechanism of the free radical/nonradical pathway was connected to the increased π–electrons flow in sp2–carbon by conjugation after the iron introduction. Meanwhile, ecotoxicological safety of TC intermediates identified to validate the superiority of the nonradical process. In this work, a new method for inducing nonradical pathway was provided in the process of PDS activation, which effectively avoided harmful intermediates generation in the process of organic contaminants degradation.

Reliability Analysis and Anti Interference Design of Instruments

Reliability Analysis and Anti Interference Design of Instruments

Electromechanical Coupling Modelling of High Speed EMUs with Rotor Field Oriented Control

According to the theory of vehicle system dynamics and rotor flux-oriented control (RFOC), an electromechanical coupling simulation model of transmission system of high-speed EMUs is established considering the effect of mechanical and electrical characteristics. Firstly, an EMUs multi-body system (MBS) model including is developed by Simpack software based on the structure and parameters of a high-speed EMUs, and a RFOC simulation model of traction transmission system is also built by the Simulink platform. Then two types of models are linked by Simpack co-simulation interface model. Consequently, the electromechanical coupling model of EMUs is developed. The computer simulation method is adopted to simulate the coupling system with RFOC. Simulation results indicate that the proposed model can effectively reveal the change of electrical performance of the high-speed EMUs, the coupling system has a good anti interference performance and robustness.

Selective rhodamine–based probe for detecting Hg2+ and its application as test strips and cell staining

A novel probe 1 for detection of Hg2+ based on rhodamine platform was developed. The probe showed a high selectivity and anti–interference capability toward Hg2+ even in the presence of other metal ions (except Cu2+) in CH3CN–H2O (7/3, v/v) solution, and the low detection limits of 0.12 μM and 0.38 μM by using absorbance and fluorescence methods, respectively. Moreover, the mechanism of detecting Hg2+ was demonstrated due to the probe hydrolyzed to rhodamine acid in the presence of Hg2+ and exhibited a characteristic absorption band at 554 nm, which was recognized via the “naked–eye”. Noticeably, the probe was successfully applied to cell staining and the colorimetric detection for Hg2+ could realize by the test strips.

Electrochemical synthesis of thin-layered graphene oxide-poly(CTAB) composite for detection of morphine

In this work, poly(cetyltrimethylammoniumbromide)/graphene oxide (poly(CTAB)/GO) composite was synthesized via in situ electropolymerisation and used as novel sensor for morphine (MO) detection. The CTAB functionalized graphene sheet offers large surface area which remarkably enhances the electrochemical response of MO compared to that of bare glassy carbon electrode (GCE). The surfactant CTAB with its hydrophilic head and hydrophobic tail plays a significant role in enhancing the catalytic property of the electrode. The electrostatic interaction between cationic group of poly (CTAB) and lone pair on nitrogen atom of tertiary amine group of MO favours the electro oxidation of tertiary amine group rather than phenolic group. A detection limit of 0.36 μM and a wide linear range of 50–60 μM feature the merits of the proposed composite in the analysis of MO. This sensor shows good repeatability, reproducibility, stability and anti interference properties. It is also tested in real samples. Schematic representation of the electrochemical behaviour of the modified electrode poly (CTAB)/GO/GCE towards morphine.

Copper(II) Electrochemical Sensor Based on Aluminon as Chelating Ionophore

In this paper, a simple and effective electrochemical sensor was performed based on the magnetic beads (MBs) and aurintricarboxylic acid ammonium salt called Aluminon (ATA) for sensitive and selective detection of Cu(II) using square wave voltammetry. The ATA/MBs/GCE electrode exhibited enhanced electrochemical response because of the high affinity to Cu(II) of the deposited layer made of the electrodeposited MBs and ATA. Under optimal conditions, a good linear response in the range from $10^{\mathbf {-6}}$ to $10^{\mathbf {-4}}$ M with a detection limit of $1.7\,\,10^{\mathbf {-7}}$ M were obtained. The developed copper sensor was further validated and successfully applied to detect Cu(II) in real water samples. Besides, the copper sensor showed a good anti interference performance, high stability, and excellent regeneration ability.

A novel heterogeneous catalyst based on reduced graphene oxide supported copper coordinated amino acid – A platform for morphine sensing

A reduced graphene oxide (RGO) supported electropolymerised copper coordinated aminoacid (Cu-poly(Ala)) was deposited on a glassy carbon electrode (GCE) by a two-step process and its application as a sensor is demonstrated herein. The prepared nanocomposite presented a novel way for the design of an electrochemical sensor by incorporating the fascinating characteristics of amino acid alanine as the molecular host providing cavities and Cu2+ as the active centre generating a platform for electrochemical deposition of RGO. The sensor was able to detect both phenolic as well as tertiary amine group of morphine (MO). A lowering of potentials by 270 mV and 145 mV compared to bare GCE was monitored, which is much lower than available reports. An enhanced rate constant of the order of 3.5 × 105 mol−1 L s−1 was obtained. This novel sensing platform for MO produced a very low detection limit of 47 nM with a very good linear dynamic range 50 nm to 80 μM. The sensor displayed good anti interference ability, stability and was successfully applied to real sample analysis.

Facile synthesis of iron phthalocyanine functionalized N,B–doped reduced graphene oxide nanocomposites and sensitive electrochemical detection for glutathione

Iron phthalocyanine (FePc) functionalized nitrogen, boron–doped reduced graphene oxide (N,B–rGO) nanocomposite (FePc/N,B–rGO) was facilely fabricated for the first time as a electrochemical platform for sensitive detection of glutathione (GSH). FePc was immobilized on N,B–rGO substrate through π–π interaction, and N,B–rGO provided FePc with a large specific surface area to improve electron transfer and maintain its electrocatalytic activity. Cyclic voltammetric measurements showed that FePc and N,B–rGO triggered the synergistic effect and exhibited a satisfactory electrocatalytic activity. By integration of FePc and N,B–rGO, the FePc/N,B–rGO/GCE sensor displayed a wide linear dynamic range from 5.0 × 10–8 M to 1.6 × 10–3 M with a low detection limit of 7.1 × 10–9 M. Besides, the electrochemical sensor presented satisfiable reproducibility, excellent anti–interference performance and long–term stability. The method was further expanded to determinate GSH in human serum sample with the recoveries between 95.0–109.0%.

A new carbazole-based colorimetric and fluorescent sensor with aggregation induced emission for detection of cyanide anion

A new carbazole-based naked-eye colorimetric and fluorescent sensor CPPB with aggregation induced emission (AIE) effect was successfully synthesized. The solid powder of CPPB emitted intense yellow fluorescence, and its emission wavelength and fluorescence intensity in DMSO/H2O solution varied with the percentage of water (fw). Nano-aggregates of CPPB molecules were prepared by increasing fw of DMSO/H2O solution, and the optimal aggregation state of CPPB was reached in 99% aqueous DMSO solution with the maximum fluorescence intensity. Moreover, CPPB displayed high selectivity and sensitivity toward cyanide anions (CN−) in 99% aqueous DMSO solution even in the presence of other competitive anions (CN−, F−, Cl−, AcO−, NO3−, I−, CO32−, HCO3−, HSO3−, SO42−, S2−, HS−, OH−, H2PO4− and HPO42−) and the reactive oxygen species (H2O2, O2·−, 1O2, t-BuOOH and ·OH). The sensing mechanism for CN− was confirmed by optical spectral studies, 1H NMR titration, HRMS spectra, Job's plot analyses and DFT calculations. Sensor CPPB for CN− detection revealed extremely low detection limit (67.4 nM), high anti–interference ability, wide pH response range (3.0–10.0) as well as the immediate response (15 s). Furthermore, the CPPB-based test strips were applied to detect CN− qualitatively and quantitatively in 100% aqueous solution.

Ag Functionalized Molybdenum Disulfide Hybrid Nanostructures for Selective and Sensitive Amperometric Hydrogen Peroxide Detection

Ag nanoparticles functionalized flower-like molybdenum disulfide (MoS2) hybrid nanostructures (AgNPs/MoS2) were successfully synthesized by a facile hydrothermal method. The structure and surface morphology were subsequently characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. The as-synthesized AgNPs/MoS2 hybrid nanostructures were modified on a glassy carbon electrode (GCE) and further utilized for amperometric hydrogen peroxide (H2O2) detection. The electrochemical behaviors and sensing performance of the AgNPs/MoS2/GCE were studied by cyclic voltammetry (CV) and single-potential amperometry methods. The obtained results have demonstrated that the developed AgNPs/MoS2/GCE amperometric sensor possesses an excellent catalytic performance toward the reduction of H2O2. The as-prepared electrochemical sensor exhibits fast response time of less than 3 s, large linear detection range of 0.025-135.2 mM (R-2=0.998) and high sensitivity of 54.5 mu A.mM(-1). cm(-2). Moreover, the developed H2O2 sensor has shown good anti interference ability, outstanding stability and reproducibility, which represents a great potential for H2O2 detection in practical applications.

A Comparative Study on “Turn‐off” Fluorimetric Nitro Aromatic Detection Using a Class of Dinulear Zinc (II) Schiff Base Complexes

AbstractFour “end‐off” compartmental ligands 2,6‐bis((E)‐((2‐(dimethylamino)ethyl)imino)methyl)‐4‐R‐phenol, where R= methyl/ isopropyl/ tertiary butyl/ chloro for HL1 – HL4 respectively, have been designed and four complexes of zinc(II) have been synthesized and structurally characterized with the aim to apply them as nitro aromatic detector by utilizing their fluorescent behavior. All the four complexes are found to be highly fluorescent in acetonitrile medium and their emission intensities are found to quench in presence of four nitro aromatics such as 2,6‐dinitrotoluene (2,6‐DNT), 4‐nitrobenzoic acid (4‐NBA), 1,3‐dinitrobenzene (1,3‐DNB), and 4‐nitrotoluene (4‐NT) with the complex 4 having the highest quenching capability. Fluorescence sensing ability and anti interference ability were done using complex 4 and 4‐NBA to establish their exclusive detection property. Stern‐Volmer experiments were performed to evaluate the quenching constants. Finally, photo physical experiments such as temperature dependent fluorescence titration study and TCSPC experiment in presence of quencher are carried out to prove the quenching mode as a dynamic.

On Line Monitoring of Partial Discharge in High Voltage Cables

Now China vigorously develop urban underground cable, the scale of the underground power grid is gradually expanding, the voltage level of the high voltage cable from the original 23 35kV to kV, and then to 110kV and even 220kV rising. In cable trench, different levels of voltage cable mixed, ditch perennially humid, even perennial water and power cable trench no monitoring equipment for use, thus for on-line monitoring caused a lot of difficulties. On line detection of the key technologies for signal extraction and anti interference technology. In this paper, a scheme of real-time partial discharge on-line monitoring for high voltage cables is designed.

Two Wheeled Robot Self Balancing Control Research

According to movement balancing and position control problem of Self Balancing Two Wheeled Robot, a method based on H∞ Robust Control was proposed. We apply it onto the MIMO nonlinear model of robot, and simulated it in the MATLAB environment The simulation results shows that the robot can be balanced in fixed position well by this method, and also it have the ability to anti interference.

Carbon functionalized mesoporous silica-based gas sensors for indoor volatile organic compounds

Indoor organic gaseous pollution is a global health problem, which seriously threats the health and life of human all over the world. Hence, it is important to fabricate new sensing materials with high sensitivity and efficiency for indoor volatile organic compounds. In this study, a series of ordered mesoporous silica-based nanocomposites with uniform carbon coatings on the internal surface of silica mesopore channels were synthesized through a simple template–carbonization strategy. The obtained mesoporous silica–carbon nanocomposites not only possess ordered mesostructures, high surface areas (up to ∼759m2g−1), large and tunable pore sizes (2.6–10.2nm), but also have the improved hydrophobicity and anti–interference capability to environmental humidity. The sensing performances of the mesoporous silica–carbon nanocomposites to volatile organic compounds, such as ethylbenzene, methylbenzene, benzene, methanol, acetone, formaldehyde, dichloromethane and tetrahydrofuran, were systematically investigated. The relationships between the sensing performances and their properties, including mesostructures, surface areas, pore sizes, carbon contents and surface hydrophilic/hydrophobic interactions, have been achieved. The mesoporous silica–carbon nanocomposites with hexagonal mesostructure exhibit outstanding performance at room temperature to benzene and acetone with high responses, short response (2–3s) and recovery (16–19s) time, strong anti–interference to environmental humidity, and long–term stability (less than ∼5% loss of the frequency shifts after 42days). Therefore, the obtained mesoporous silica–carbon nanocomposites have a hopeful prospect in the field of environmental air quality monitoring.

A rapid triple-mode fluorescence switch assay for immunoglobulin detection by using quantum dots-gold nanoparticles nanocomposites

The immunoglobulins, most of them are glycoprotein, play an important role on humoral immune. We herein report a triple-modenano sensor with a fluorometric readout based on CdTe quantum dots (QDs) and gold nanoparticles (AuNPs) for discriminative detection of immunoglobulin. Immunoglobulins fall into several classes, each with its own functional characteristics. In this research, we use chicken egg yolk immunoglobulin (IgY) as an example to establish the specific detection methods. IgY is the only antibody existing in chicken egg yolk, which has many significant advantages. We used anti-IgY and staphylococcal protein A (SPA) to make the detection discriminatively to IgY. The immune interaction between QDs-SPA and anti-IgY-AuNPs leads to drastic quenching (turning off) of the donor by a fluorescence resonance energy transfer (FRET) process. After the addition of IgY, anti-IgY-AuNPs peel off from the QDs-SPA surface and bind to IgY due to competitive immunoreactions, resulting in the restoration of the fluorescence intensity of QDs (turning on). Consequently, this process can be utilized for the selective detection of IgY via optical responses. This proposed assay demonstrated a favorable anti interference ability and highly selectivity toward IgY with a detection limit of 1.16ng/mL. More importantly, the nanosensor could not only function in aqueous solution for IgY detection with high sensitivity but also exhibit sensitive responses toward IgY in complicated biological environments, demonstrating its potential in bioanalysis, which might be significant in biochemical field in the future.