Potassium-sensitive G-quadruplexDNA for sensitive visible potassium detection
2009; Royal Society of Chemistry; Volume: 135; Issue: 1 Linguagem: Inglês
10.1039/b913036e
ISSN1364-5528
AutoresXuan Yang, Tao Li, Bingling Li, Erkang Wang,
Tópico(s)RNA Interference and Gene Delivery
ResumoA novel visual method for K(+) detection is developed utilizing a K(+)-sensitive G-quadruplex DNA named PS5.M as the sensing element. In the absence of K(+), PS5.M is in a random coil state and does not bind hemin. Upon addition of K(+), PS5.M folds into the quadruplex structure stabilized by K(+). Such quadruplex structure is able to bind hemin to form the hemin-G-quadruplex DNAzyme that catalyzes the H(2)O(2)-mediated oxidation of colorless 3,3',5,5'-tetramethylbenzidine to the blue product. Under the optimal conditions, the color change can be clearly observed with the naked eye in the concentration range from 2 to 1000 microM. Through this facile approach, K(+) can be detected down to 2 microM, with high selectivity against other cations. In view of its simplicity, sensitivity and specificity, our developed visual method for K(+) detection would potentially be utilized for bioassays and K(+)-sensitive test paper.
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