A DNA–Fullerene Conjugate as a Template for Supramolecular Chromophore Assemblies: Towards DNA‐Based Solar Cells

Abstract

A fullerene was covalently attached to a (dA)20 template that serves as structural scaffold to self-assemble an ordered and mixed array of ethynyl-pyrene- and ethynyl-Nile-red-nucleoside conjugates. Fluorescence spectroscopy revealed evidence for energy transfer between the two different chromophores. Moreover, fluorescence quenching is significantly enhanced by the attached fullerene in mixed assemblies of different chromophore ratios. This indicates exciton dissociation by electron transfer from the photo-generated exciton on the chromophore stack to the fullerene. The fullerene-DNA-conjugate was integrated as a photo-active layer in solar cells that showed charge-carrier generation in the spectral regime of all three components of the conjugate. This work clearly demonstrates that DNA is suitable as structural element for chromophore assemblies in future organic optoelectronic devices, such as solar cells.

Control of helical chirality in supramolecular chromophore–DNA architectures

“…17,18 We evidenced the assembly of ethnyl pyrenes 19 and ethynyl nile reds 20 as 2 0 -deoxyuridine conjugates specifically along oligo-2 0 -deoxyadenosines as DNA templates to obtain supramolecular DNA-chromophore assemblies as functional photoactive layers in solar cells. 21 Most recently, we showed that ethynyl pyrene and ethynyl nile red can be assembled in a sequence-programmable fashion controlled by the DNA template. 22 The construction of p-functional supramolecular chromophore assemblies faces the challenge that chromophores have to be kept in close proximity but complete self-quenching has to be ruled out.…”

Programmable and Sequence‐Selective Supramolecular Assembly of Two Different Chromophores along DNA Templates

“…These results are in accordance with CD measurements of mixed Py-dU and Nr-dU assemblies, where as imilarb ehavior was observed. [11,12] Fluorescence-detected circular dichroism( FDCD) couplesc onventionalC Dw ith fluorescences pectroscopy,w hiche nables to probe selectively chiral emissive entities, (even) in the presence of many nonemissive chromophores, such as DNA bases. [17] Thus, only those DNA-baseda ssemblies that showedP y-dAp fluorescence resultedi naFDCD spectrum.…”

From Interaction to Function in DNA‐Templated Supramolecular Self‐Assemblies

“…Furthermore, the same group studied these mixed assemblies of nile red and pyrene derivative templated by an oligodeoxyadenine (ssDNA) template, which was covalently linked to a fullerene derivative, as the prototype acceptor in organic solar cells. The supramolecular assembly was integrated in the active layer of a solar cell, and the results demonstrated charge‐carrier generation in the spectral range where the three π‐conjugated molecules absorb . This is a promising result that demonstrates the potential of DNA‐templated self‐assembly for organic optoelectronic devices.…”