A highly sensitive fluorometric method is described for the determination of mercury(II) ions. It is based on (a) the use of a DNA probe containing thymine-thymine mismatches that are employed as Hg(II) recognition elements, (b) subsequent toehold binding, and (c) endocuclease-assisted signal amplification. Target recycling is triggered by exonuclease III. This produces a large amount of ssDNA (defined as primer). Then, the generated primer-initiated strand displacement reaction with the help of polymerase and nicking endonuclease releases the free fluorophore-labelled probe. Under excitation at 532 nm, the fluorescent probe displays emission with a peak at 582 nm. The sensitivity of this method is improved by introduction of nicking endonuclease. The working range of the assay extends from 20 pM to 10 nM, and the detection limit is as low as 6 pM of Hg(II). Graphical abstract Schematic presentation of the fluorometric method for determination of mercury(II). By using a special structure of thymine-thymine mismatches, target-induced toehold binding and enzyme-assisted signal amplification strategy were employed. This method is selective and good performance in real sample application.
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http://dx.doi.org/10.1007/s00604-019-3683-3 | DOI Listing |
Biosensors (Basel)
September 2024
Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea.
Mercury ions (Hg) are toxic heavy metals present in the environment that pose significant health risks. An advanced detection system could allow for a prompt response and alleviate serious damage to humans. In this study, we developed a cost-effective, on-site detection method for Hg using a multicomponent nucleic acid enzyme (MNAzyme)-assisted nucleic acid lateral flow assay (NALFA).
View Article and Find Full Text PDFBiosens Bioelectron
November 2024
Department of Biomechatronics Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea; Department of MetaBioHealth, Sungkyunkwan University, Suwon, 16419, Republic of Korea; Department of Biopharmaceutical Convergence, Sungkyunkwan University, Suwon, 16419, Republic of Korea. Electronic address:
Nanoscale
August 2024
Department of Physics, Alexandru I. Cuza University, 700506 Iasi, Romania.
The presence of non-essential metals in the environment as contaminants is prone to cause hazardous health problems following accumulation in the human body and the ensuing toxic effects. This calls for continuous discovery and innovation in the realm of developing easy-to-operate, cheap and sensitive sensors. Herein, we describe the proof of concept approach for designing a molecular receptor-like, chimeric sensor based on the pore-forming peptide alamethicin (Alm), tethered a linker with an ultrashort peptide nucleic acid (PNA) moiety, capable of generating functional ion channel oligomers in planar lipid membranes.
View Article and Find Full Text PDFAnal Chem
July 2024
Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Material Science and Engineering, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, China.
Novel hollow AuAg nanoboxes (AuAg NBs) were designed for an innovative electrochemiluminescence (ECL) sensor to ultrasensitively detect Pb and Hg with the aid of DNAzyme and "thymine-Hg-thymine" ("T-Hg-T") structure. AuAg NBs are employed as an excellent surface plasma resonance (SPR) source, as well as an effective coreaction accelerator for the CoNi NFs/SO system to greatly improve ECL performance. To detect Pb, the DNAzyme catalyzes the cleavage of ribonucleic acid targets into numerous small nucleic acid fragments, leading to an ECL signal.
View Article and Find Full Text PDFFront Microbiol
June 2021
Department of Chemistry, Bioscience and Environmental Technology, Faculty of Science and Technology, University of Stavanger, Stavanger, Norway.
DNA polymerase III mis-insertion may, where not corrected by its 3'→ 5' exonuclease or the mismatch repair (MMR) function, result in all possible non-cognate base pairs in DNA generating base substitutions. The most thermodynamically unstable base pair, the cytosine (C)⋅C mismatch, destabilizes adjacent base pairs, is resistant to correction by MMR in , and its repair mechanism remains elusive. We present here evidence that C⋅C mismatch can be processed by base excision repair initiated by the formamidopyrimidine-DNA glycosylase (Fpg) protein.
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