Molecular Chromophore-DNA Architectures With Fullerenes: Optical Properties and Solar Cells

Abstract

Supramolecular chemistry allows the construction of complex molecular architectures and the design of collective photophysical properties. DNA is an attractive template to build such supramolecular architectures due to its helical structure, the defined distances between the bases and the canonical base pairing that results in precise control of the chromophore position. The tailored properties of DNA-templated supramolecules eventually allow their implementation into optoelectronic applications. For the generation of free charge carriers from photo-generated excitons, fullerenes can be utilized. We synthesized two fullerene derivates, one of which binds by electrostatic interactions to single-stranded DNA, while the other contains two 2′-deoxyuridine moieties and assembles specifically along oligo-2′-deoxyadenosines (dA20) as DNA template. The DNA-directed assembly of both fullerenes in aqueous solution was investigated by UV/Vis absorbance and circular dichroism (CD) spectroscopy. The specific interactions with DNA make fullerenes with the 2′-deoxyuridine moieties a significantly better component for supramolecular DNA architectures. We studied the fluorescence quenching of both fullerenes with a DNA chromophore assembly. To investigate one of the key properties for optoelectronic applications, that is the supramolecular structure of the DNA-based assemblies in the solid phase, we characterized the CD of supramolecular chromophore-DNA architectures in thin films. Remarkably, the helical chirality of the chromophore assemblies that is induced by the DNA template is conserved even in the solid state. Upon implementation into organic solar cells, the external quantum efficiency measurements showed charge carrier generation on all three chromophore components of the DNA assemblies. The fullerenes with the 2′-deoxyuridine moieties enhance the quantum efficiency of the conversion process significantly, demonstrating the potential of DNA as structural element for ordering chromophores into functional π-systems, which may be employed in future organic solar cells.

Exploring the Bioactive Potentials of C60-AgNPs Nano-Composites against Malignancies and Microbial Infections

“…The C 60 molecule is a typical football-shaped structure with carbon (C) atoms in the pentagon and hexagon configurations. It has been named after the well-known scientist Buckminster Fuller, resembling its structure to geodesic domes [ 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. It has been previously reported that C 60 molecules can be prepared using bottom-up techniques using arch discharge, chemical route of Chemical Vapour Deposition (CVD), etc., where refined structures of C 60 when visualized under High electron microscopy such as HR-TEM, FE-SEM could be employed for visualizing and analyzing its native configurations.…”

Photoresponsive Porphyrin‐DNA Complexes Constructed through Intercalation‐like Binding

“…In this context, DNAs that can be synthetically and biochemically produced are suitable biomolecules to construct functional materials because DNA can offer a flexible design of complex nanostructures and incorporation of functional units in a desirable position [5–6] . DNA has been widely employed as a structural scaffold and building block to assemble functional chromophores on the programmed self‐assembled structure of DNA [7–9] and to construct light‐harvesting systems [10–14] and molecular photonic wires [1,15–18] …”

“…[1][2][3][4] In this context, DNAs that can be synthetically and biochemically produced are suitable biomolecules to construct functional materials because DNA can offer a flexible design of complex nanostructures and incorporation of functional units in a desirable position. [5][6] DNA has been widely employed as a structural scaffold and building block to assemble functional chromophores on the programmed self-assembled structure of DNA [7][8][9] and to construct light-harvesting systems [10][11][12][13][14] and molecular photonic wires. [1,[15][16][17][18] Porphyrin (Por) derivatives whose photochemical properties can be modulated through peripheral substituents and coordinated metal ions are of interest due to their photochemical characteristics of suitable energy and electron transfer properties.…”

DNA-templated control of chirality and efficient energy transport in supramolecular DNA architectures with aggregation-induced emission

“…6 The bottom-up approach is a powerful concept to achieve this goal, 7 and DNA is a unique template with sequence specificity through the recognition by hydrogen bonding to arrange chromophores in in a precise way, 8 and this DNA-like structure persists also in the solid state for optoelectronic applications. 9 The most precise, covalent incorporation of chromophores into DNA is limited to 5-10 units in a row, until the yields drops. 10,11 The non-covalent self-assembly of nucleosides along singlestranded DNA is an important alternative, for instance with naththalenes 12 and porphyrines 13,14 through binding to T 20 or T 40 .…”