Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7233923 | Biosensors and Bioelectronics | 2013 | 5 Pages |
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 (Rct) of the sensor using a redox couple of [Fe(CN)6]3â/4â 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 Rct. The Rct increased with K+ concentration, and the plot of Rct against the logarithm of K+ concentration is linear over the range from 0.1Â nM to 1Â mM with a detection limit of 0.1Â nM. 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.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Zhengbo Chen, Liang Chen, He Ma, Tong Zhou, Xiaoxiao Li,