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DNAzyme Sensor for the Detection of Ca2+ Using Resistive Pulse Sensing.
Heaton, Imogen; Platt, Mark.
Affiliation
  • Heaton I; Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK.
  • Platt M; Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK.
Sensors (Basel) ; 20(20)2020 Oct 17.
Article in En | MEDLINE | ID: mdl-33080851
ABSTRACT
DNAzymes are DNA oligonucleotides that can undergo a specific chemical reaction in the presence of a cofactor. Ribonucleases are a specific form of DNAzymes where a tertiary structure undergoes cleavage at a single ribonuclease site. The cleavage is highly specificity to co-factors, which makes them excellent sensor recognition elements. Monitoring the change in structure upon cleavage has given rise to many sensing strategies; here we present a simple and rapid method of following the reaction using resistive pulse sensors, RPS. To demonstrate this methodology, we present a sensor for Ca2+ ions in solution. A nanoparticle was functionalised with a Ca2+ DNAzyme, and it was possible to follow the cleavage and rearrangement of the DNA as the particles translocate the RPS. The binding of Ca2+ caused a conformation change in the DNAzyme, which was monitored as a change in translocation speed. A 30 min assay produced a linear response for Ca2+ between 1-9 µm, and extending the incubation time to 60 min allowed for a concentration as low as 0.3 µm. We demonstrate that the signal is specific to Ca2+ in the presence of other metal ions, and we can quantify Ca2+ in tap and pond water samples.
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Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Biosensing Techniques / Calcium / DNA, Catalytic Type of study: Diagnostic_studies Language: En Journal: Sensors (Basel) Year: 2020 Document type: Article Affiliation country:

Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Biosensing Techniques / Calcium / DNA, Catalytic Type of study: Diagnostic_studies Language: En Journal: Sensors (Basel) Year: 2020 Document type: Article Affiliation country: