A novel electrochemical DNAzyme sensor for the amplified detection of Pb2+ ions

Yang, Xiaorong; Xu, Juan; Tang, Xuemei; Liu, Huixiang; Tian, Danbi

doi:10.1039/c002137g

Cited by 157 publications

(78 citation statements)

References 27 publications

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“…With a large dynamic range (6 orders of magnitude), a detection limit down to 30 fM was obtained based on three times standard deviation of the blank, which is at least 500-fold lower than those of previously reported fluorescence methods. 22,[26][27][28][29] This sensitivity is also much higher than those of several electrochemical and electrochemiluminescence approaches 24,25,30,31 and is even comparable to the surface plasmon resonance-based biosensor. 32 The details are summarized in Table 1.…”

Section: Optimization Of Sensing Conditionsmentioning

confidence: 89%

Polymerase/nicking enzyme synergetic isothermal quadratic DNA machine and its application for one-step amplified biosensing of lead (II) ions at femtomole level and DNA methyltransferase

et al. 2014

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Herein, we propose a novel and universal biosensing platform based on a polymerase-nicking enzyme synergetic isothermal quadratic DNA machine (ESQM). This platform tactfully integrates two signal amplification modules, strand displacement amplification (SDA) and nicking enzyme signal amplification (NESA), into a one-step system. A bifunctional DNA probe with a stem-loop structure was designed to be partly complementary to the SDA product and digested substrate of NESA for bridging SDA and NESA. ESQM can be performed by using only the enzymes and buffer involved in the SDA module. In the presence of a target, this DNA machine is activated to afford a high quadratic amplified signal. Using Pb 2+ and DNA adenine methylation (Dam) methyltransferase (MTase) as analytes, a sensitive biosensing platform is demonstrated. Low detection limits of 30 fM Pb 2+ and 0.05 U ml − 1 Dam MTase were achieved within a short assay time (40 min), which were each superior to those of most previously reported methods. This DNA machine exhibited high selectivity for Pb 2+ . Furthermore, the successful detection of complex environmental water samples demonstrated the applicability of the proposed strategy in real samples, holding great potential for its application in environmental monitoring, biomedical research and clinical diagnosis. INTRODUCTIONSignal amplification technologies have a critical role in molecular biology research, environmental and food monitoring, forensic identification and clinical diagnosis. Since its creation in 1985, polymerase chain reaction has become the most well-known and widely used amplification technique. 1 However, this technique suffers from an intrinsic drawback, the requirement of precision thermal cycling between three different temperatures in a costly thermal cycler, limiting its popularization and application in point-of-care testing. On the other hand, various alternative isothermal amplification methods, such as rolling circle amplification (RCA), 2,3 strand displacement amplification (SDA), 4 loop-mediated isothermal amplification, 5,6 nicking enzyme signal amplification (NESA) 7-9 and the exponential amplification reaction (EXPAR) 10 have been proposed in the past two decades. These isothermal methods have been developed mainly based on some new findings in molecular biology concerning DNA synthesis and some accessory proteins together with their mimicking in vitro for nucleic acid amplification. Among these methods, EXPAR has been widely used, which is attributed to its rapid amplification kinetics (several minutes) and exceedingly high amplification efficiency (10 6 -to 10 9 -fold). For example, Ye's group 11 and Zhang's group 12,13 have proposed several interesting methods for the highly sensitive detection of microRNA and protein based on EXPAR, respectively. Nevertheless, the EXPAR-based methods involve the weaknesses of early phase non-specific background amplification resulting from the binding of the polymerase to the single-stranded template. 14 Conversely, the linear amplification ...

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Section: Optimization Of Sensing Conditionsmentioning

confidence: 89%

Polymerase/nicking enzyme synergetic isothermal quadratic DNA machine and its application for one-step amplified biosensing of lead (II) ions at femtomole level and DNA methyltransferase

et al. 2014

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“…Electrochemical sensors for Pb 2+ were reported using Pb 2+ -induced cleavage of nucleic acid substrates on AuNPs by 8-17 DNAzymes to enable the detachment (Fig. 7c) [249] or attachment [258] of AuNPs onto a DNAcoated electrode. The DNA on AuNPs permits attachment of large amounts of electrochemically active metal complexes, thus providing a large signal enhancement on the electrode in the presence of Pb 2+ [249,258].…”

Section: Nucleic Acid Cleaving/ligating Dnazymes and Aunps For Biosenmentioning

confidence: 99%

“…7c) [249] or attachment [258] of AuNPs onto a DNAcoated electrode. The DNA on AuNPs permits attachment of large amounts of electrochemically active metal complexes, thus providing a large signal enhancement on the electrode in the presence of Pb 2+ [249,258]. Graphene sheets decorated by DNAzyme-functionalized AuNPs were also used to detect L-histidine and Pb 2+ as the cofactors of two DNAzymes, respectively [261,278].…”

Section: Nucleic Acid Cleaving/ligating Dnazymes and Aunps For Biosenmentioning

confidence: 99%

DNAzyme-Functionalized Gold Nanoparticles for Biosensing

Xiang

Tan

et al. 2013

Advances in Biochemical Engineering/Biotechnology

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Recent progress in using DNAzyme-functionalized gold nanoparticles (AuNPs) for biosensing is summarized in this chapter. A variety of methods, including those for attaching DNA on AuNPs, detecting metal ions and small molecules by DNAzyme-functionalized AuNPs, and intracellular applications of DNAzyme-functionalized AuNPs are discussed. DNAzyme-functionalized AuNPs will increasingly play more important roles in biosensing and many other multidisciplinary applications. This chapter covers the recent advancement in biosensing applications of DNAzyme-functionalized gold nanoparticles, including the detection of metal ions, small molecules, and intracellular imaging.

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“…Especially in developing electrochemical biosensors, highly selective detection strategy is the central research topic [1,2]. Mercury, a neurotoxicant, is considered to be one of highly toxic heavy metal ions and well known toxic contaminants in aquatic ecosystems.…”

Section: Introductionmentioning

confidence: 99%

A Simple and Highly Sensitive Electrochemically Reduced p‐Nitrobenzoic Acid Film Modified Sensor for Determination of Mercury

et al. 2014

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Pulse techniques in electron paramagnetic resonance (EPR) allow for a reduction in measurement times and increase in sensitivity but require the synthesis of paramagnetic probes with long relaxation times. Here it is shown that the recently synthesized phosphonated trityl radical possesses long relaxation times that are sensitive to probe the microenvironment, such as oxygenation and acidity of an aqueous solution. In principle, application of Fourier transform EPR (FT‐EPR) spectroscopy makes it possible to acquire the entire EPR spectrum of the trityl probe and assess these microenvironmental parameters within a few microseconds. The performed analysis of the FT‐EPR spectra takes into consideration oxygen‐, proton‐, buffer‐, and concentration‐induced contributions to the spectral shape, therefore enabling quantitative and discriminative assessment of pH, pO2, and concentrations of the probe and inorganic phosphate.

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A novel electrochemical DNAzyme sensor for the amplified detection of Pb2+ ions

Abstract: A novel amplification strategy based on DNAzyme functionalized gold nanoparticles was employed to enhance the sensitivity of an electrochemical sensor for detection of Pb2+. The detection limit is 0.028 nM, which is much lower than for other electrochemical DNAzyme sensors.

Cited by 157 publications

References 27 publications

Polymerase/nicking enzyme synergetic isothermal quadratic DNA machine and its application for one-step amplified biosensing of lead (II) ions at femtomole level and DNA methyltransferase

Polymerase/nicking enzyme synergetic isothermal quadratic DNA machine and its application for one-step amplified biosensing of lead (II) ions at femtomole level and DNA methyltransferase

DNAzyme-Functionalized Gold Nanoparticles for Biosensing

A Simple and Highly Sensitive Electrochemically Reduced p‐Nitrobenzoic Acid Film Modified Sensor for Determination of Mercury

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