FRETsensoren

FRETsensoren, or Förster Resonance Energy Transfer sensors, are molecular tools used to detect and quantify biological processes at the nanoscale. They leverage the biophysical phenomenon of FRET, where energy is transferred non-radiatively from a donor fluorophore to an acceptor fluorophore when they are in close proximity, typically 1-10 nanometers. This energy transfer is highly dependent on the distance between the two fluorophores.

A FRETsensor is constructed with a donor and an acceptor fluorophore linked by a specific molecular probe or recognition element. This element is designed to undergo a conformational change or to bind to a target molecule of interest. When the target molecule is present, it causes the probe to change its shape, altering the distance between the donor and acceptor. If the distance decreases to within the FRET range, energy transfer occurs, resulting in a decrease in donor fluorescence intensity and a corresponding increase in acceptor fluorescence intensity. Conversely, if the distance increases, FRET efficiency decreases.

By monitoring the ratio of donor to acceptor fluorescence, researchers can infer the presence or absence of the target molecule, or quantify its concentration. FRETsensoren have found broad applications in molecular biology, including the study of protein-protein interactions, enzyme activity, DNA hybridization, and ion concentration changes. Their sensitivity and ability to report on molecular events in real-time make them invaluable for both in vitro assays and in vivo imaging. The design of FRETsensors is versatile, allowing for the development of probes tailored to a wide array of biological questions.