FRET enhancement in aluminum nanoapertures

Metal nanoapertures known as zero-mode waveguides (ZMWs) are receiving a large interest as they concentrate light into nanoscale volumes and enable single molecule fluorescence experiments at micromolar concentrations. Within the large single molecule fluorescence toolbox, FRET is certainly one of the most widely used. Therefore it is tempting to associate ZMWs with FRET. However, such experiments are challenged by the complex influence the metal may have on the FRET process.

In a recent Chem Phys Chem article, we quantify the FRET rates and efficiencies between individual donor-acceptor pairs in aluminum zero-mode waveguides. We also compare the FRET results between ZMWs milled in gold and aluminum, and discuss the influence of plasmon resonance effects.

Given the large interest raised by aluminum ZMWs and FRET separately, we believe that our detailed report will help to expand the application of ZMWs as new devices for enhanced single molecule FRET at physiological concentrations.