The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform

Ruo Yuan - One of the best experts on this subject based on the ideXlab platform.

  • click chemistry reaction triggered 3d dna Walking Machine for sensitive electrochemical detection of copper ion
    Analytical Chemistry, 2018
    Co-Authors: Dianyong Tang, Min Qing, Ying Tang, Jin Zhang, Ruo Yuan
    Abstract:

    Herein, for the first time, we engineered click chemistry reaction to trigger a 3D DNA Walking Machine for ultrasensitive electrochemical detection of copper ion (Cu2+), which provided a convenient access to overcome the shortcomings of poor selectivity and limited amplification efficiency in traditional determination of Cu2+. Click chemistry reaction drove azido-S2 to bind with alkynyl-S1 for the formation of a walker probe on aminated magnetic polystyrene microsphere@gold nanoparticles (PSC@Au), which opened the hairpin-locked DNAzyme. In the presence of magnesium ion (Mg2+), the unlocked DNAzyme was activated to cleave the self-strand at the facing ribonucleotide site, accompanied by the release of product DNA (S3) and the walker probe. Therefore, the walker probe was able to open the adjacent hairpin-locked DNAzyme strand and then be released by DNAzyme cleavage along the PSC@Au-DNAzyme track. Eventually, the liberated single-strand S3 induced catalytic hairpin assembly (CHA) recycling, resulting in t...

  • ultrasensitive electrochemiluminescence biosensor for microrna detection by 3d dna Walking Machine based target conversion and distance controllable signal quenching and enhancing
    Analytical Chemistry, 2017
    Co-Authors: Ziqi Xu, Yaqin Chai, Linli Liao, Haijun Wang, Ruo Yuan
    Abstract:

    In this study, an electrochemiluminescence (ECL) regenerated biosensor was reported to sensitively detect microRNA through 3D DNA Walking Machine and “on–off–super on” strategy. First, 3D DNA Walking Machine with higher efficiency of payload releasing and superior signal amplification than those of the traditional DNA Walking Machine was initially introduced in the ECL system for converting target microRNA to intermediate DNA and achieving significant signal amplification. Second, the distance between CdS:Mn quantum dots and Au nanoparticles was increased with the hybridization of intermediate DNA and Au nanoparticles modified S2, which weakened the energy transfer for ECL signal recovering and excited the surface plasma resonance for further enhancing the signal to construct the on–off–super on biosensor. Such an on–off–super on strategy not only reduced the ECL background signal but also increased the detection sensitivity. Impressively, the elaborately designed biosensor could be regenerated by Lambda ...

  • bi directional dna Walking Machine and its application in an enzyme free electrochemiluminescence biosensor for sensitive detection of micrornas
    Analytical Chemistry, 2017
    Co-Authors: Lichun Peng, Yaqin Chai, Pu Zhang, Ruo Yuan
    Abstract:

    Herein, a dual microRNA (miRNA) powered bi-directional DNA Walking Machine with precise control was developed to fabricate an enzyme-free biosensor on the basis of distance-based electrochemiluminescence (ECL) energy transfer for multiple detection of miRNAs. By using miRNA-21 as the driving force, the DNA walker could move forth along the track and generated quenching of ECL response due to the proximity between Au nanoparticles (AuNPs) and Mn2+ doped CdS nanocrystals (CdS:Mn NCs) film as the ECL emitters, realizing ultrasensitive determination of miRNA-21. Impressively, once miRNA-155 was introduced as the driving force, the walker could move back along the track automatically, and surface plasmon resonance (SPR) occurred owing to the appropriate large separation between AuNPs and CdS:Mn NCs, achieving an ECL enhancement and realizing ultrasensitive detection of miRNA-155. The bi-directional movement of the DNA walker on the track led to continuous distance-based energy transfer from CdS:Mn NCs film by ...

  • a ferrocene switched electrochemiluminescence off on strategy for the sensitive detection of cardiac troponin i based on target transduction and a dna Walking Machine
    Chemical Communications, 2015
    Co-Authors: Ziqi Xu, Yongwang Dong, Jiyang Li, Ruo Yuan
    Abstract:

    A ferrocene-switched electrochemiluminescence “off–on” sensor is proposed on the basis of target transduction and a DNA Walking Machine for the sensitive detection of cardiac troponin I (cTnI). The proposed method offers high selectivity with a low detection limit of 0.016 pg mL−1, and provides a universal platform for detecting a wide range of targets, including other proteins and DNAs, by changing the molecular recognition elements to the corresponding antibodies, aptamers or DNA probes.

  • a restriction enzyme powered autonomous dna Walking Machine its application for a highly sensitive electrochemiluminescence assay of dna
    Nanoscale, 2015
    Co-Authors: Ying Chen, Yun Xiang, Ruo Yuan, Yaqin Chai
    Abstract:

    The construction of a restriction enzyme (Nt.AlwI)-powered DNA Walking Machine and its application for highly sensitive detection of DNA are described. DNA nanostructure tracks containing four overhang sequences with electrochemiluminescence (ECL) labels and complementary to the walker (target DNA) are self-assembled on the sensing electrode. The walker hybridizes with the complementary sequences on the tracks and forms specific recognition sites for Nt.AlwI, which cleaves the overhang sequences, releases the ECL labels and enables directional movement of the walker along the tracks. The formation of the nanostructure tracks and the Nt.AlwI-assisted cleavage of the overhang sequences in the presence of the walker are verified by using polyacrylamide gel electrophoresis analysis and cyclic voltammetry. The successive movement of the walker on the nanostructure tracks leads to continuous removal of massive ECL labels from the sensing electrode, which results in a significantly amplified suppression of the ECL emission for highly sensitive detection of sequence-specific DNA down to 0.19 pM. Results show that this DNA Walking Machine can also offer single-base mismatch discrimination capability. The successful application of the DNA Walking Machine for sequence-specific DNA detection can thus offer new opportunities for molecular Machines in biosensing applications.

Yaqin Chai - One of the best experts on this subject based on the ideXlab platform.

  • ultrasensitive electrochemiluminescence biosensor for microrna detection by 3d dna Walking Machine based target conversion and distance controllable signal quenching and enhancing
    Analytical Chemistry, 2017
    Co-Authors: Ziqi Xu, Yaqin Chai, Linli Liao, Haijun Wang, Ruo Yuan
    Abstract:

    In this study, an electrochemiluminescence (ECL) regenerated biosensor was reported to sensitively detect microRNA through 3D DNA Walking Machine and “on–off–super on” strategy. First, 3D DNA Walking Machine with higher efficiency of payload releasing and superior signal amplification than those of the traditional DNA Walking Machine was initially introduced in the ECL system for converting target microRNA to intermediate DNA and achieving significant signal amplification. Second, the distance between CdS:Mn quantum dots and Au nanoparticles was increased with the hybridization of intermediate DNA and Au nanoparticles modified S2, which weakened the energy transfer for ECL signal recovering and excited the surface plasma resonance for further enhancing the signal to construct the on–off–super on biosensor. Such an on–off–super on strategy not only reduced the ECL background signal but also increased the detection sensitivity. Impressively, the elaborately designed biosensor could be regenerated by Lambda ...

  • bi directional dna Walking Machine and its application in an enzyme free electrochemiluminescence biosensor for sensitive detection of micrornas
    Analytical Chemistry, 2017
    Co-Authors: Lichun Peng, Yaqin Chai, Pu Zhang, Ruo Yuan
    Abstract:

    Herein, a dual microRNA (miRNA) powered bi-directional DNA Walking Machine with precise control was developed to fabricate an enzyme-free biosensor on the basis of distance-based electrochemiluminescence (ECL) energy transfer for multiple detection of miRNAs. By using miRNA-21 as the driving force, the DNA walker could move forth along the track and generated quenching of ECL response due to the proximity between Au nanoparticles (AuNPs) and Mn2+ doped CdS nanocrystals (CdS:Mn NCs) film as the ECL emitters, realizing ultrasensitive determination of miRNA-21. Impressively, once miRNA-155 was introduced as the driving force, the walker could move back along the track automatically, and surface plasmon resonance (SPR) occurred owing to the appropriate large separation between AuNPs and CdS:Mn NCs, achieving an ECL enhancement and realizing ultrasensitive detection of miRNA-155. The bi-directional movement of the DNA walker on the track led to continuous distance-based energy transfer from CdS:Mn NCs film by ...

  • a restriction enzyme powered autonomous dna Walking Machine its application for a highly sensitive electrochemiluminescence assay of dna
    Nanoscale, 2015
    Co-Authors: Ying Chen, Yun Xiang, Ruo Yuan, Yaqin Chai
    Abstract:

    The construction of a restriction enzyme (Nt.AlwI)-powered DNA Walking Machine and its application for highly sensitive detection of DNA are described. DNA nanostructure tracks containing four overhang sequences with electrochemiluminescence (ECL) labels and complementary to the walker (target DNA) are self-assembled on the sensing electrode. The walker hybridizes with the complementary sequences on the tracks and forms specific recognition sites for Nt.AlwI, which cleaves the overhang sequences, releases the ECL labels and enables directional movement of the walker along the tracks. The formation of the nanostructure tracks and the Nt.AlwI-assisted cleavage of the overhang sequences in the presence of the walker are verified by using polyacrylamide gel electrophoresis analysis and cyclic voltammetry. The successive movement of the walker on the nanostructure tracks leads to continuous removal of massive ECL labels from the sensing electrode, which results in a significantly amplified suppression of the ECL emission for highly sensitive detection of sequence-specific DNA down to 0.19 pM. Results show that this DNA Walking Machine can also offer single-base mismatch discrimination capability. The successful application of the DNA Walking Machine for sequence-specific DNA detection can thus offer new opportunities for molecular Machines in biosensing applications.

Jiadong Huang - One of the best experts on this subject based on the ideXlab platform.

  • entropy driven spliced dna Walking Machine for label free electrochemical detection of antibiotics
    Sensors and Actuators B-chemical, 2020
    Co-Authors: Rufeng Zhang, Shasha Li, Jingfeng Wang, Xiaonan Qu, Yihan Zhao, Yu Wang, Jiadong Huang, Jinghua Yu
    Abstract:

    Abstract Herein, we have integrated an entropy-driven DNA Walking Machine into electrochemical platform for label-free sensing of antibiotics. As far as we know, this work is the first time that entropy-driven DNA Machine has been used for antibiotics detection. The designed DNA Machine is activated by a target-triggered catalytic hairpin assembly to form a spliced DNA walker long-arm. Then the autonomous and progressive spliced walk long-arm on electrode surface via the toehold-mediated strand displacement reaction induces continuous release of signal probe (SP) from three-stranded DNA complex. The freedom of SP leads to the generation of abundant G-quadruplex DNAzyme which can catalyze decomposition of hydrogen peroxide, so an extremely intense electrochemical response is observed. Our spliced DNA Walking Machine precedes the previous DNA Machine in terms of economy and stability due to the strategy of entropy-driven and label-free, and possesses a detection limit to 0.96 pM for detection of ampicillin. Moreover, this DNA Machine is expected to detect more analytes by using corresponding aptamer probes. Hence, the entropy-driven DNA walker provides an efficient and practical platform for small molecule analysis.

  • exonuclease iii powered dna Walking Machine for label free and ultrasensitive electrochemical sensing of antibiotic
    Sensors and Actuators B-chemical, 2019
    Co-Authors: Rufeng Zhang, Shasha Li, Xiaonan Qu, Yihan Zhao, Yu Wang, Jiadong Huang
    Abstract:

    Abstract Herein, an Exonuclease III (Exo III)-powered DNA Walking Machine has been integrated into electrochemical sensing for label-free and highly sensitive detection of antibiotics. The electrochemical sensing interface is prepared by co-assembly of hemin aptamer-containing DNA track (DT) and DNA walker (DW)-locking probe (LP) duplex on gold electrode surface. The specific target and aptamer interaction triggers Exo III-assisted cyclic amplification, releasing the unlocking probe (UP) that is used for the deblocking of DW. Then the autonomous moving of DW on electrode surface is propelled via Exo III digestion of hybridized DT. The consumption of DT induces the formation of G-quadruplex/hemin DNAzyme that can catalyze the reduction of H 2 O 2 , thus a significantly strong current signal is released. Using ampicillin as a model analyte, the proposed biosensor achieves a detection limit of 0.76 pM within a linear detection range from 1 pM to 10 nM. Additionally, this biosensing strategy can be readily extended for the detection of wide variety of analytes by using corresponding target recognition probes. Therefore, the proposed strategy indeed creates a highly sensitive and label-free electrochemical sensing platform for molecular diagnosis applications.

Rüdiger Dillmann - One of the best experts on this subject based on the ideXlab platform.

  • reactive reflex based control for a four legged Walking Machine
    Robotics and Autonomous Systems, 2003
    Co-Authors: Jan Albiez, Karsten Berns, Tobias Luksch, Rüdiger Dillmann
    Abstract:

    Abstract This paper presents methods and experiments of a reactive control architecture for a four-legged Walking Machine. Starting with a description of the existing control architecture we introduce the concepts of reflexes and behaviours as well as their integration into the system. The used reactive network and the development process is described in detail. The paper concludes with a description of various experiments.

  • An activation based behaviour control architecture for Walking Machines
    2002
    Co-Authors: Jan Albiez, Karsten Berns, Tobias Luksch, Rüdiger Dillmann
    Abstract:

    This paper introduces a behaviour network architecture for controlling Walking Machines. The behavior coordination problem is solved by distributing the activation of the behaviours according to the sensoric information as well as the specified task of the robot. This approach heavily emphasises the loop-back of the behaviour activities and the satisfaction of their goals. The results of initial experiments with this architecture on the four-legged Walking Machine BISAM are also presented.

  • adaptive periodic movement control for the four legged Walking Machine bisam
    International Conference on Robotics and Automation, 1999
    Co-Authors: Jan Albiez, Karsten Berns, H Jedele, Rüdiger Dillmann
    Abstract:

    Presents an adaptive control architecture for the four legged Walking Machine BISAM. This architecture uses coupled neuro-oscillators as representation of periodic behaviours on different control levels such as joint movement, leg control and leg coordination. Coupled neuro-oscillators together with adaptive sensor based reflexes provide a robust and efficient representation for quadrupedal locomotion and support the use of online learning approaches to realize adaptation and optimization of locomotion behaviours.

  • Neural networks for the control of a six-legged Walking Machine
    Robotics and Autonomous Systems, 1995
    Co-Authors: Karsten Berns, Rüdiger Dillmann, Stefan Piekenbrock
    Abstract:

    Abstract In this paper a hierarchical control architecture for a six-legged Walking Machine is presented. The basic components of this architecture are neural networks which are taught in using examples of the control process. It is shown how the basic components “leg control” and “leg coordination” have been implemented by recurrent and feedforward networks respectively. The teaching process and the tests of the Walking behaviour have mainly been done in a simulation system. First tests of the leg control on our real Walking Machine LAURON are also described.

Ziqi Xu - One of the best experts on this subject based on the ideXlab platform.