A single-mode nonadiabatic tapered optical fiber (NATOF) biosensor based on ssDNA aptamer for detection of potassium ion (K⁺) was developed. Upon binding to K+, the G-rich single-stranded DNA can fold into the G-quadruplex structure, thus allowing the formation of G-quadruplex complex after incubation with K⁺ which is led to changing in refractive index (RI). Under optimum conditions, the wavelength shift was proportional to the concentration of K⁺ in the range of 10 ×10^-4 to 2×10^-2 mM. A detection limit of 4.5×10^-4 was achieved. Moreover, this method was able to detect K⁺ with high selectivity in the presence of Na⁺ ion of biological fluids.

Date Published: 2 June 2014
PDF: 4 pages
Proc. SPIE 9157, 23rd International Conference on Optical Fibre Sensors, 91574K (2 June 2014); doi: 10.1117/12.2059036

Published in SPIE Proceedings Vol. 9157:
23rd International Conference on Optical Fibre Sensors
José M. López-Higuera; Julian D. C. Jones; Manuel López-Amo; José Luis Santos, Editor(s)