White light emission produced by CTMA-DNA nanolayers embedded with a mixture of organic light-emitting molecules

Abstract

Researchers have started to recognize that biomaterial-based devices and sensors can be used in the development of high-performing environmentally-friendly technologies. In this regard, DNA can be utilized as a competent scaffold for hosting functional nanomaterials to develop a designated platform in the field of bionanotechnology. Here, we introduce a novel methodology to construct CTMA-modified DNA nanolayers (CDNA NLs) embedded with single (e.g., red, green, and blue), double (violet, yellow, and orange), and triple (white) iridium-based organic light-emitting materials (OLEMs, including Ir(piq) 2 (acac) for red, Ir(ppy) 2 (acac) for green, FIrpic for blue) that can serve as active light-emitting layers.The OLEM-embedded CDNA NLs were fabricated using simple solution processes, and their spectral properties were investigated via Fourier-transform infrared (FTIR), X-ray photoelectron (XPS), UV-Vis, and photoluminescence (PL) spectroscopies. FTIR analysis of OLEM-embedded CDNA NLs suggested that the complexes are stable and chemically inert. XPS revealed the various modes of interaction between OLEMs and CDNA. The evidence of interactions between blue OLEM and CDNA was demonstrated by peak shifts. The wide band gap characteristics ($4.76 eV) and relatively high optical quality (no absorption in the visible region) of OLEM-embedded CDNA NLs were observed in UV-Vis absorption measurements. We observed PL emission in OLEM-embedded CDNA NLs, which was caused by the energy transfer from CDNA to OLEMs (ligand-centered and metal to ligand charge transfer). Lastly, a white light-emitting OLEM-embedded CDNA thin film was constructed using a combination of appropriate concentrations of red, green, and blue OLEMs. Its characteristic was demonstrated through spectral measurements. In addition, colour coordinates were plotted in the International Commission on Illumination (CIE) colour space, which confirmed the colour identity for the developed colours (including white). Consequently, the OLEM-embedded CDNA NLs can likely be used as a functional material in bioimaging and bio-photonics.

Nanomaterial-Embedded DNA Films on 2D Frames

“…The emission spectra of CDNA-OLEM are obtained with excitation wavelength of 350 nm. The emission peaks of CDNA-OLEM are observed by the movement of excited charge carriers from higher energy states to lower energy states . Wavelengths of the emission peaks for CDNA-OLEM R , CDNA-OLEM G , and CDNA-OLEM B are observed at 610, 515, and 469 nm, respectively (Figure a).…”

“…The emission peaks of CDNA-OLEM are observed by the movement of excited charge carriers from higher energy states to lower energy states. 44 Wavelengths of the emission peaks for CDNA-OLEM R , CDNA-OLEM G , and CDNA-OLEM B are observed at 610, 515, and 469 nm, respectively (Figure 5a). CDNA films embedded with two (three) types of OLEMs show two (three) emission peaks, as shown in Figure 5b for CDNA-OLEM RG (Figure 5c for CDNA-OLEM RGB ).…”

Solvent Effect to the Uniformity of Surfactant-Free Salmon-DNA Thin Films

“…Specifically, the band gap of DNA makes it favorable to function as a hole injection/electron blocking layer in organic-based electronic devices [ 7 , 8 , 9 ]. Previous authors have demonstrated the ability of DNA to improve LED performance [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ] and as a component in the fabrication of photovoltaics [ 14 , 15 , 16 , 17 ]. Moreover, DNA films can be used as a matrix and doped with functional materials that can alter the optical and electronic properties of the thin film, which may be useful for different types of organic devices [ 18 , 19 , 20 ].…”

“…Despite the potential of DNA-based thin-film devices, not much study has been reported to systematize the fabrication of DNA thin films from aqueous and alcohol solutions [ 14 ]. Previous research has focused on thin films fabricated from surfactant modifications, primarily with cetyltrimethylammonium (CTMA) modified DNA thin films with consistent results [ 13 , 15 , 16 , 17 , 21 , 22 , 23 , 24 , 25 ]. Thus, research has focused on controlling the electronic and optical properties of surfactant-modified thin films, and applications have relied on characterizing results from DNA–CTMA complexes.…”