Good Anti-interference Research Articles

A highly selective colorimetric and fluorescent probe Eu(tdl)2abp for H2S sensing: Application in live cell imaging and natural water

Using 4-([2,2′: 6′, 2′- terpyridin] -4′-yl) -N, N-dimethylaniline (tdl) as auxiliary ligand and 6-azido-2,2′-bipyridine (abp) as recognition ligand, a europium complex fluorescent probe Eu(4-([2,2′: 6′, 2′-terpyridin] -4′ -yl) -N, N-dimethylaniline)2–6-azido-2,2′-bipyridine Eu(tdl)2abp for efficient and specific recognition of hydrogen sulfide (H2S) was successfully synthesized and characterized by NMR and MS. Eu(tdl)2abp represented “on-off” fluorescence signals for H2S and its color changes could be identified with naked eyes. Eu(tdl)2abp had short response time (2 min) to H2S, high selectivity and good anti-interference, large stokes shift (207 nm). In various samples, when H2S existed, the azide group was reduced to amine group, resulting in closed fluorescence signal, and the fluorescence intensity reached the degree of quenching without being affected by other interference. At the same time, there was a good linear relationship between relative fluorescence intensity and H2S concentration with the detection limit (LOD) of 0.64 μM. The sensing mechanism of Eu(tdl)2abp to detect H2S was characterized by 1H NMR and HR-MS. Eu(tdl)2abp was used with success for the sensitive detection of H2S in natural water and living cells.

A highly sensitive strategy for glypican-3 detection based on aptamer/gold carbon dots/magnetic graphene oxide nanosheets as fluorescent biosensor

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths in China. Glypican-3 (GPC3) is a specific antigen related to HCC, which is widely used in clinical detection as a reliable marker of HCC. In this paper, a highly sensitive homogeneous apatasensor was designed for GPC3 detection based on fluorescence resonance energy transfer (FRET) where the GPC3 aptamer labelled gold carbon dots (AuCDs-GPC3Apt) are used as a donor and magnetic graphene oxide (Fe3O4/GO) nanosheets are used as an acceptor. A one-step hydrothermal method was used to synthesize AuCDs to provide sufficient fluorescence. The FRET phenomenon exists between AuCDs-GPC3Apt and Fe3O4/GO, which weakens the fluorescence intensity of the whole system. When the target GPC3 is added to the FRET system, the fluorescent AuCDs-GPC3Apt binds to the GPC3 and forms a folded structure, which leads to AuCDs-GPC3Apt separation from Fe3O4/GO nanosheets. The Fe3O4/GO is then magnetically separated so that the fluorescence of free labelled AuCDs-GPC3Apt is restored. Under the optimum conditions, the fluorescence recovery rate is linearly correlated with the concentration of GPC3 (5-100ng·mL-1) and the detection limit is 3.01ng·mL-1 (S/N = 3). This strategy shows recoveries from 98.76 to 101.29% in real human serum samples and provides an immediate and effective detection method for the quantification of GPC3 with great potential applications for early diagnosis of HCC. A sensitive homogeneous FRET-based apatasensor was designed for GPC3 detection where the AuCDs-GPC3Apt is a donor and Fe3O4/GO nanosheets are an acceptor. The GPC3 fluorescent aptasensor combines wider output range with low cost, high specificity, and good anti-interference.

Photon arrival sequence analysis of laser heterodyne signal with a Geiger-mode APD array

A heterodyne detection mechanism with Geiger-mode avalanche photodiode detector arrays is proposed for optical systems to achieve high sensitivity and good anti-interference. In contrast to the conventional processing method of photon arrival sequence, where the step of incoherent accumulation is canceled, the beat frequency is only obtained in this paper by the coherent superposition of phase-matched sequences, which can alleviate or even reduce the effect of the initial phase drift between the frames of the beat frequency signal. After phase matching of the beat signal, the power spectral density intensity of coherent superposition is greater than that of incoherent accumulation.

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.

RAPID ELECTROCHEMICAL DETECTION OF CARBENDAZIM IN VEGETABLES BASED ON CARBOXYL FUNCTIONALIZED MULTI-WALLED CARBON NANOTUBES

At present, the commonly used methods for the detection of benzimidazole fungicides include high performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), fluorescence spectrometry and so on. These methods have high sensitivity and accurate results, but they have disadvantages such as complicated pretreatment, long time consuming, expensive equipment and professional operators. Electrochemical sensor detection method has the advantages of high sensitivity, simple operation, low cost and easy on-site inspection, etc., which has attracted extensive attention in the field of pesticide residue detection and analysis. In order to realize the rapid detection of carbendazim content in vegetables, an electrochemical rapid detection method was established by using Carboxyl Functionalized Multi-Walled Carbon Nanotubes (MWCNTs-COOH) modified glassy carbon electrode. In this study, MWCNTs-COOH with special functional groups and large specific surface area were used to modify electrodes to improve the adsorption and enrichment of CBZ on the electrode and amplify the electrochemical signal, aiming to establish a highly sensitive electrochemical rapid detection technology for CBZ. The results showed that: the modified electrode functionalized with MWCNTs-COOH could significantly improve the electron transfer rate on the electrode surface, which made the detection sensitivity of carbendazim higher. The linear range of detection was 0,3 μM~20 μM, and the detection limit was determined as low as 0,06 μM. In this study, MWCNT-COOH with better conductivity, adsorption and stability was used to modify electrode, and constructed the MWCNT-COOH/GCE, which improved the adsorption and accumulation of CBZ, effectively promoted the electron transfer on the surface of the electrode, accelerated the response speed of the electrode and improved the current response, to realize the rapid and sensitive detection of trace CBZ in vegetables. This method had high sensitivity, good anti-interference, and detection stability. It was of great significance to detect carbendazim in vegetables.

An efficient glucose sensor thermally calcined from copper-organic coordination cages.

Due to the harmfulness of diabetes, a fast and efficient glucose detector is particularly important. Metal-organic polyhedron (MOP) provides a porous framework and a special matrix, which makes it an excellent precursor for electrochemical detection. Herein, we report a novel MOP as a precursor for the preparation of an electrocatalytic detector for glucose. The new metal-organic polyhedron of Cu4(TPDC)4 can be solvothermally obtained and characterized by X-ray crystallography, which can be thermally converted into nanosized copper oxides embedded into graphitic carbon layers (MOP-CO). The as-prepared MOP-CO electrode is further applied to glucose detection, which shows a fast response time (<1s) in a wide linear range of 0-4000μM and high sensitivity of 2720μAmM-1cm-2, as well as low detection limit (26nM(S/N=3)), good anti-interference, repeatability and stability (>3600s).

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.

Spatially-directed magnetic molecularly imprinted polymers with good anti-interference for simultaneous enrichment and detection of dual disease-related bio-indicators.

As the changes of biomarkers directly reflect the occurrence of degenerative diseases, accurate detection of biomarkers is of great significance for disease diagnosis and control. However, single index detection has high uncertainties to accurately reflect the pathological characteristics because of the complexity of the human internal environment and the extremely trace concentration of indicators. To this end, a method for simultaneous detection of dual-biomarkers based on anti-interference magnetic molecularly imprinted polymers (D-mag-MIPs) is thereby proposed, and successfully applied in human urine analysis for the detection of Parkinson's disease bio-indicators 4-dihydroxyphenylacetic acid (DOPAC) and dopamine (DA). In this work, carboxyl functionalized ferric oxide served as a magnetic core, laying a solid foundation for batch detection. Hyperbranched polyethylenimine, whose abundant amino groups can provide multiple interaction forces to templates with high affinity, is employed as a functional monomer. Relative to single-template MIPs, D-mag-MIPs achieve the detection of dual bio-indicators in a one-time test, reducing the false positive result probability and enhancing the detection accuracy. The proposed methodology has been evaluated to exhibit good anti-interference, satisfactory precision, low detection limits, wide linear ranges and fast batch detection for DA and DOPAC. This work thus offers an alternative and efficient pathway for convenient batch detection of dual bio-indicators from biofluids at once.

Carbon dots embedded hydrogel spheres for sensing and removing rifampicin

Although a plethora of carbon dots (CDs) based sensors continue to spring up, hardly any study on CDs acting as fluorescent probe for detecting rifampicin (RF) has been reported so far. Furthermore, no CDs hydrogel spheres (HSs) were fabricated and utilized as optical sensors as well as absorbent to recognize and remove pollutants. In this paper, bright blue luminescent CDs possess remarkable fluorescence sensing ability for the detection of RF, with high selectivity, outstanding sensitivity (LOD, 0.46 μM) and good anti-interference, which enabled CDs to successfully applied for the quantitative determination of RF in different real water samples. Furthermore, in order to integrate the advantages of hydrogel and CDs, fluorescent CDs HSs were fabricated, which could not only act as efficient optical sensors to recognize RF, but also conduct as absorbent to facilitate RF removal. The present work offers a new insight into taking advantage of CDs for the detection of RF in a convenient and efficient way.

In situ formation of silver nanoparticles via hydride generation: A miniaturized/portable visual colorimetric system for arsenic detection in environmental water samples

A miniaturized/portable visual colorimetric system based on hydride generation headspace solid phase extraction (HG-HS-SPE) was proposed for arsenic detection by naked eyes. As(III) was transformed into AsH3via hydride generation process, the volatile AsH3 was introduced into reaction bottle and reacted with AgNO3 subsequently. Silver nanoparticles (Ag NPs) were generated in situ, resulting in the color changed from white to black, it could be readout by naked eyes or a smartphone application (color extraction, for RGB readout). The interferences from 9 common ions and 10 conventional hydride generation elements were discussed, the results demonstrated that the proposed method exhibit a good anti-interference. The proposed visual colorimetric method was further applied to seven water samples and their spiked samples, and a certified reference water sample (GBW08605) for demonstrating its accuracy and applicability.

Convenient Heme Nanorod Modified Electrode for Quercetin Sensing by Two Common Electrochemical Methods.

Quercetin (Qu) is one of the most abundant flavonoids in the human diet. High concentrations of Qu can easily cause adverse effects and induce inflammation, joint pain and stiffness. In this study, Heme was used as a sensitive element and deposited and formed nanorods on a glassy carbon electrode (GCE) for the detection of Qu. The Heme/GCE sensor was characterized using scanning electron microscopy (SEM), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. Under optimized conditions, the developed sensor presented a linear concentration ranging from 0.1 to 700 μmol·L−1 according to the CV and DPV methods. The detection limit for the sensor was 0.134 μmol·L−1 and its sensitivity was 0.12 μA·μM−1·cm−2, which were obtained from CV analysis. Through DPV analysis we obtained a detection limit of 0.063 μmol·L−1 and a sensitivity of 0.09 μA·μM−1·cm−2. Finally, this sensor was used to detect the Qu concentration in loquat leaf powder extract, with recovery between 98.55–102.89% and total R.S.D. lower than 3.70%. The constructed electrochemical sensor showed good anti-interference, repeatability and stability, indicating that it is also usable for the rapid detection of Qu in actual samples.

Facile fabrication of Tb3+-functionalized COF mixed-matrix membrane as a highly sensitive platform for the sequential detection of oxolinic acid and nitrobenzene

A novel Tb3+-functionalized covalent organic framework-based polymer mixed-matrix membrane (Tb3+@COF MMM) has been successfully fabricated by incorporating the highly stable Tb3+@PI-COF as filler into polyvinylidene fluoride (PVDF) solution. Compared with pure COF membrane, MMM exhibits its good flexibility, processability and high detection sensitivity. The obtained Tb3+@COF-MMM (M) can be employed as a highly sensitive sensing platform for the sequential detection of oxolinic acid (OA) and nitrobenzene (NB) based on a “off-on-off” process. M has performed its great selectivity, high sensitivity, and low detection limit for detecting OA with “turn-on” mechanism. Moreover, owing to the good chemical stability and anti-interference of M sensor, it is prospective to efficiently detect residues of OA in serum or river water. After the detection of M-15 toward OA, the obtained fluorescent M-15/OA exhibits the rapid quenching, facile manipulation, cycling utility and low detection limits for sensing NB solution and vapor. This work has proposed a typical case of developing flexible Ln3+-functionalized COF-based polymer mixed-matrix membrane as a highly sensitive sensing platform for detecting OA and NB, simultaneously revealed the applied potentiality of M for monitoring animal health and environmental pollution.

Durable and flexible Ag-nanowire-embedded PDMS films for the recyclable swabbing detection of malachite green residue in fruits and fingerprints

Swab sampling for the trace surface-enhanced Raman scattering (SERS) analysis of an aromatic dye (e.g., malachite green, MG) residue in fruits as well as fingerprints is promising due to its practical utility and efficiency in food security and forensic science. However, the durability and recyclability of the SERS substrates pose an enormous challenge. In this study, a novel flexible film was constructed by embedding a commercial Ag nanowire suspension into a polydimethylsiloxane film (Ag NWs@PDMS), which simultaneously exhibits SERS activity, durability and recyclability. High SERS performance was still maintained, even against 20 times stretchability, corrosion by HNO3, destruction by ultrasonication and a broad working temperature of −20 ℃ to 80 ℃. Excellent recyclability for MG sensing was achieved in ten cycles. Ag NWs@PDMS was successfully used for the quantitative detection of MG in juices of fruits (such as apple and pear) by drop dripping, with a limit of detection of 10 nM and good anti-interference. Meanwhile, the sensitive detection of the MG residue (only 3 ng/cm2) on fruits was enabled by the on-site surface swabbing by recycling for five cycles. Portable detection of the MG residue was further achieved from the 10th fingerprint after successively touching a dye drop onto the functional film combined with a portable Raman spectrometer.

Fabrication of a new self-assembly compound of LiTaMoO6 with cationic manganese porphyrin utilized as an ascorbic acid and dopamine sensor

A novel highly selective nanocomposite MnTMPyP/TaMoO6 was successfully synthesized and developed for simultaneous detection of Ascorbic acid (AA) and dopamine (DA). Firstly, the host material LiTaMoO6 was synthesized by the high temperature solid phase method. After the exfoliation/restacking process of the host material, the nanocomposite was formed through electrostatic self-assembly. The structure and morphology were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectrometer analysis (EDS), ultraviolet-visible (UV–vis) and Fourier transform infrared spectrometer (FTIR). And the electrochemical behaviors of the modified electrode were further explored by cyclic voltammetry (CV), electrochemical impedance analysis (EIS), and differential pulse voltammetry (DPV). Under the optimal conditions, the MnTMPyP/TaMoO6 provides a high sensitivity and selectivity in detecting AA and DA with linear response ranges of 12–674 μM. The resulting detection limit is also calculated as 0.97 and 0.54 μM, respectively. In addition, the MnTMPyP/TaMoO6 nanocomposite exhibits excellent stability, reproducibility, and good anti-interference.

Highly sensitive and selective electrochemical sensor based on porous graphitic carbon nitride/CoMn2O4 nanocomposite toward heavy metal ions

The combination of semiconductors and binary transition metal oxides has drawn growing interest in terms of their enhanced electrochemical analysis performance in electrochemical sensing. A new type of highly sensitive and selective sensor was designed and developed by constructing a nanocomposite system of porous graphitic carbon nitride and CoMn2O4 (pg-C3N4/CoMn2O4) to detect heavy metal ions of Cd(II) and Pb(II). The morphological and structural characteristics of pg-C3N4/CoMn2O4 nanocomposite were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The optimized current responses obtained through the square wave anodic stripping voltammetry (SWASV) of Cd(II) and Pb(II) increased linearly with their concentration in wide linear dynamic ranges of 0.5–7.0 μM and 0.2–4.4 μM, respectively, as well as low detection limits of 0.021 μM for Cd(II) and 0.014 μM for Pb(II). Further, the proposed sensor was successfully applied for the determination of Cd(II) in actual water samples accomplished with the value of recoveries ranging from 93.0%–106.0%. In addition, good anti-interference, favorable reproducibility, excellent stability and repeatability of the sensor enable it feasible for the detection of heavy metal ions.

Research on Sports Video Image Based on Clustering Extraction

Today, with the continuous sports events, the major sports events are also loved by the majority of the audience, so the analysis of the video data of the games has higher research value and application value. This paper takes the video of volleyball, tennis, baseball, and water polo as the research background and analyses the video images of these four sports events. Firstly, image graying, image denoising, and image binarization are used to preprocess the images of the four sports events. Secondly, feature points are used to detect the four sports events. According to the characteristics of these four sports events, SIFT algorithm is adopted to detect the good performance of SIFT feature points in feature matching. According to the simulation experiment, it can be seen that the SIFT algorithm can effectively detect football and have good anti-interference. For sports recognition, this document adopts the frame cross-sectional cumulative algorithm. Through simulation experiments, it can be seen that the grouping algorithm can achieve a recognition rate of more than 80% for sporting events, so it can be seen that the recognition algorithm is suitable for recognizing sports events videos.

Experimental Research on the Sensitivity of Partial Discharge Ultra High Frequency Sensor Structure Parameters

With the development of intelligent high voltage switch, online gas insulated switchgear discharge detection technology has been more and more widely applied. Because of the high sensing sensitivity and good antiinterference performance of build-in partial discharge sensor, it is currently required to install them on gas insulated switchgear products with voltage levels of 220 kV and above at the factory. The structural parameters of the build-in partial discharge sensor is of great importance to its sensing sensitivity. Therefore, in this paper, the influence of the structure change on the sensitivity of axisymmetric gas insulated switchgear build-in partial discharge sensor is experimentally studied. A practical gas insulated switchgear test model was established in the laboratory, and the frequency domain measurement system based on Spectrogram analyzer and synchronous sweep signal generator was adopted. By comparing the insertion loss generated by the build-in sensor when receiving sweep signal, the influence of structural parameter changes on the sensing sensitivity was analyzed. The results show that the diameter of the build-in sensor should be matched with the diameter of the hand-hole. The match of the larger diameter of the hand-hole and the smaller diameter of the sensor can increase the sensing sensitivity, but when the diameter of the sensor is close to the diameter of the hand-hole, the sensitivity will be significantly reduced. In addition, metal bolts with the sensor electrode and its insulating support fixed to the hand-hole cover can also result in a significant reduction in sensing sensitivity. Using the same measuring principle and system, the propagation attenuation characteristics of partial discharge ultra high frequency signal in gas insulated switchgear typical structures (linear and L-shaped structures) are also experimentally studied. The results show that the average attenuation of partial discharge ultra high frequency signal in gas insulated switchgear along the linear distance is 0.3 dB/m, and the attenuation through every L-shaped structure is 4.2 dB.

Novel nano-engineered environmental sensor based on polymelamine/graphitic-carbon nitride nanohybrid material for sensitive and simultaneous monitoring of toxic heavy metals

Heavy metal ions (HMIs) pollution is always a serious issue worldwide. Therefore, monitoring HMIs in environmental water is an important and challenging step to ensure environmental health and human safety. In this study, we spotlight an effortless, single-step in-situ electrochemical polymerization deposition technique to fabricate a novel, low-cost, efficient, nano-engineered poly(melamine)/graphitic-carbon nitride nanonetwork (PM/g-C3N4) modified screen-printed carbon electrode (SPE) for sensitive, selective, and simultaneous electrochemical monitoring of toxic HMIs in environmental waters. g-C3N4 nanomaterial was prepared using melamine as a precursor via pyrolysis technique. As-prepared g-C3N4 and melamine monomer were electrochemically in-situ polymerized/deposited over pre-anodized SPE (ASPE) using cyclic voltammetry technique. XRD, XPS, and SEM were engaged to characterize the developed electrode. The fabricated PM/g-C3N4/ASPE was applied as an environmental sensor to selective and simultaneous electrochemical detection of Pb2+ and Cd2+ ions using differential pulse voltammetry technique. The developed sensor displayed excellent selectivity and sensitivity towards Pb2+ and Cd2+ with limit of detections of 0.008 µM and 0.02 µM, respectively. The fabricated PM/g-C3N4/ASPE sensor exhibits superior stability, repeatability, good anti-interference, and applicability for recognition of Pb2+ and Cd2+ ions in real water samples. These results proved that developed environmental sensor is low-cost, efficient, practical platform for rapid, selective, simultaneous monitoring of HMIs in the environment.

Fabrication of three-component hydrogen-bonded covalent-organic polymers for ciprofloxacin decontamination from water: adsorption mechanism and modeling

A three-component hydrogen-bonded covalent organic polymer, namely JLUE-HCOP-66, was fabricated via a facile multiple-linking-site solvothermal approach to overcome the weakness of poor function complexity and limited structure diversity of the pure covalent skeletons. The as-prepared JLUE-HCOP-66 polymers were employed to decontaminate ciprofloxacin (CIP), a popular F-quinolones (FQNs) antibiotic, from water and exhibited satisfactory adsorption performance. Specifically, JLUE-HCOP-66 polymers have high adsorption capacity with the maximum contribution of 111.1 mg/g according to the Langmuir model, good antiinterference to NaCl salts, and excellent regeneration property. The pH-dependent experiment results signified the probably dominated mechanism of electrostatic interaction. In addition, adsorption studies and structural characterization in combination illustrated that the pore-filling effect, hydrogen bonding formation might also govern the whole process, accompanied by electrostatic interaction, dipole-dipole complexation, π-π EDA interaction, and hydrophobic-hydrophobic interaction besides. Moreover, electrostatic potentials, as well as the frontier molecular orbital distributions (HOMO and LUMO) of CIP and JLUE-HCOP-66 fragment, were calculated using density functional theory to theoretically support the research. Furthermore, the response surface methodology (RSM) according to the CCD matrix was used to not only study the interactive and cooperative effects of initial CIP concentration, initial pH, ionic strength along with JLUE-HCOP-66 dosage on CIP removal using JLUE-HCOP-66 but also optimize the operation conditions. Given the peculiar structure and functional feature, this work could hopefully bring HCOPs into the practical applications of such challenging and persistent ciprofloxacin potent removal with further large-scale efficiency.

An amplified electrochemical aptasensor for ochratoxin A based on DNAzyme-mediated DNA walker

• An amplified electrochemical aptasensor for ochratoxin A was developed. • Ag + -dependent DNAzyme was used to drive DNA walker for signal amplification. • The aptasensor showed higher sensitivity, lower LOD and good anti-interference. In this work, a novel signal-on electrochemical aptasensor was designed for ochratoxin A (OTA) detection based on DNAzyme-mediated DNA walker. Double-stranded DNA (dsDNA), formed by the hybridization between OTA aptamer and DNA walker, and Hairpin DNA (HP) containing adenosine ribonucleotide (rA) site were immobilized on the electrode surface. In the presence of OTA, the competitive binding of OTA with aptamer caused dsDNA to dissociate, resulting in that DNAzyme sequence in DNA walker was exposed. With the addition of Ag + , DNAzyme-mediated DNA walker was activated and sheared HP on the electrode surface cyclically, which reduced the negative charge density and improved the transfer rate on the electrode surface for signal amplification. The peak current increased by 4.58 times with addition of Ag + than that without addition of Ag + . The proposed aptasensor exhibited a good linear relationship in the OTA concentrations from 0.001 ng/mL to 5 ng/mL, and the limit of detection was 0.1 pg/mL. The aptasensor showed good anti-interference toward AFB 1 , FB 1 , and ZEN. The aptasensor was applied to detect OTA in spiked corn samples and wine samples, and the average recoveries were 94.5%–97.7% and 92.0%–97.8%, respectively.