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Aptamer biosensor for label-free impedance spectroscopy detection of potassium ion based on DNA G-quadruplex conformation.
- Source :
-
Biosensors & Bioelectronics . Oct2013, Vol. 48, p108-112. 5p. - Publication Year :
- 2013
-
Abstract
- Abstract: Herein, a label-free and highly sensitive electrochemical impedance spectroscopy (EIS) aptasensor for the detection of potassium ion (K+) was developed based on a conformational change in which a K+-stabilized single stranded DNA (ssDNA) with G-rich sequence was used as the recognition element. In the measurement of K+ ions, the change in interfacial electron transfer resistance (R ct) of the sensor using a redox couple of [Fe(CN)6]3−/4− as the probe was monitored. In the presence of K+, the G-rich DNA folded into the G-quadruplex structure, and then K+ can bind to the G-quadruplex structure, leading to an increase in the R ct. The R ct increased with K+ concentration, and the plot of R ct against the logarithm of K+ concentration is linear over the range from 0.1nM to 1mM with a detection limit of 0.1nM. Other metal ions, such as Ca2+, Mg2+, Na+, Li+, Al3+, Zn2+, Cu2+, and Ni2+ caused no notable interference on the detection of K+. The scheme reported herein is applicable to the detection of other kinds of G-rich aptamer-binding chemicals and biomolecules. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 09565663
- Volume :
- 48
- Database :
- Academic Search Index
- Journal :
- Biosensors & Bioelectronics
- Publication Type :
- Academic Journal
- Accession number :
- 89278998
- Full Text :
- https://doi.org/10.1016/j.bios.2013.04.007