DNAzyme Sensor for the Detection of Ca2+ Using Resistive Pulse Sensing.
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.
Key words
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: