Emission Detection of Mercuric Ions in Aqueous Media Based-on Dehybridization of DNA Duplexes

• Published in: Bulletin of the Korean Chemical Society Vol. 32; no. 9; pp. 3223 - 3228
• Main Authors: Oh, Byul-Nim, Wu, Qiong, Cha, Mi-Sun, Kang, Hee-Kyung, Kim, Jin-Ah, Kim, Ka-Young, Rajkumar, Eswaran, Kim, Jin-Heung
• Format: Journal Article
• Language: Korean
• Published: 2011
• Subjects: Mercuric ion sensing; Metal-to-ligand transfer emission; Poly(dT); DNA intercalation; switch Ru compound; Light; Mismatch detection
• ISSN: 0253-2964; 1229-5949

To quantify the presence of mercuric ions in aqueous solution, double-stranded DNA (dsDNA) of poly(dT) was employed using a light switch compound, $Ru(phen)_2(dppz)^{2+}$ (1) which is reported to intercalate into dsDNA of a right-handed B-form. Addition of mercuric ions induced the dehybridization of poly(dT)${\cdot}$poly(dA) duplexes to form a hairpin structure of poly(dT) at room temperature and the metal-to-ligand charge transfer emission derived from the intercalation of 1 was reduced due to the dehybridization of dsDNA. As the concentration of $Hg^{2+}$ was increased, the emission of 1 progressively decreased. This label-free emission method had a detection limit of 0.2 nM. Other metal ions, such as $K^+$, $Ag^+$, $Ca^{2+}$, $Mg^{2+}$, $Zn^{2+}$, $Mn^{2+}$, $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$, $Cd^{2+}$, $Cr^{3+}$, $Fe^{3+}$, had no significant effect on reducing emission. This emission method can differentiate matched and mismatched poly(dT) sequences based on the emission intensity of dsDNA.