Flexible Nanoporous Liquid Crystal Networks as Matrixes for Förster Resonance Energy Transfer (FRET)

Förster resonance energy transfer (FRET) is important, not only in the fields of biology and biophysics but also in optoelectronics and light guiding systems. Different matrixes are being investigated that facilitate FRET, including zeolites and metal–organic frameworks. In this work, a matrix for FRET generation is proposed: nanoporous liquid crystal networks. These liquid crystal networks can be easily processed and can align dichroic fluorescent dyes. A base treatment can create nanopores in the network, which are then able to absorb a second fluorescent dye in an aqueous phase while still retaining good alignment. Using lifetime measurements, we provide proof that even in this nonoptimized system, around 70% of the energy was transferred via the FRET mechanism from one dye to the other. Liquid crystal networks have many advantages over current matrixes as they are easy to fabricate as well as flexible and could be modified to selectively and reversely absorb dyes, allowing many applications.