Morphological and Optoelectronic Characteristics of Double and Triple Lanthanide Ion-Doped DNA Thin Films

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• 作者：Mallikarjuna Reddy Kesama ; Sreekantha Reddy Dugasani ; Sanghyun Yoo ; Prathamesh Chopade ; Bramaramba Gnapareddy ; Sung Ha Park
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：June 8, 2016
• 年：2016
• 卷：8
• 期：22
• 页码：14109-14117
• 全文大小：726K
• 年卷期：0
• ISSN：1944-8252

文摘

Double and triple lanthanide ion (Ln³⁺)-doped synthetic double crossover (DX) DNA lattices and natural salmon DNA (SDNA) thin films are fabricated by the substrate assisted growth and drop-casting methods on given substrates. We employed three combinations of double Ln³⁺-dopant pairs (Tb³⁺–Tm³⁺, Tb³⁺–Eu³⁺, and Tm³⁺–Eu³⁺) and a triple Ln³⁺-dopant pair (Tb³⁺–Tm³⁺–Eu³⁺) with different types of Ln³⁺, (i.e., Tb³⁺ chosen for green emission, Tm³⁺ for blue, and Eu³⁺ for red), as well as various concentrations of Ln³⁺ for enhancement of specific functionalities. We estimate the optimum concentration of Ln³⁺ ([Ln³⁺]_O) wherein the phase transition of Ln³⁺-doped DX DNA lattices occurs from crystalline to amorphous. The phase change of DX DNA lattices at [Ln³⁺]_O and a phase diagram controlled by combinations of [Ln³⁺] were verified by atomic force microscope measurement. We also developed a theoretical method to obtain a phase diagram by identifying a simple relationship between [Ln³⁺] and [Ln³⁺]_O that in practice was found to be in agreement with experimental results. Finally, we address significance of physical characteristics—current for evaluating [Ln³⁺]_O, absorption for understanding the modes of Ln³⁺ binding, and photoluminescence for studying energy transfer mechanisms—of double and triple Ln³⁺-doped SDNA thin films. Current and photoluminescence in the visible region increased as the varying [Ln³⁺] increased up to a certain [Ln³⁺]_O, then decreased with further increases in [Ln³⁺]. In contrast, the absorbance peak intensity at 260 nm showed the opposite trend, as compared with current and photoluminescence behaviors as a function of varying [Ln³⁺]. A DNA thin film with varying combinations of [Ln³⁺] might provide immense potential for the development of efficient devices or sensors with increasingly complex functionality.