For the first time, wave-particle duality has been observed in a biomolecule. The team of physicists at the University of Vienna in Austria have also observed wave-like behaviour in the most massive molecule yet - a fluorinated 'buckyball'. It is twice as large as the previously biggest molecule known to exhibit quantum wave-like behaviour.
The signature of wave-particle duality in quantum particles is the wave-like interference pattern produced when a beam of particles passes through a 'double-slit'. Wave-particle duality has been seen in electrons, atoms and small molecules but not in the macroscopic world due to the wavelength being so small for large objects that we cannot detect their interference in a practical experiment.
The biomolecules used were tetraphenylporphyrin molecules. These are biological molecules present in chlorophyll and haemoglobin with a diameter is around 2 nm.
The experiment consisted of sublimating the porphyrin molecules in an oven and then passing them through a new type of interferometer with three sets of diffraction gratings, each separated from each other by about 38 cm. The first grating produces a coherent beam of molecules. The second produces the interference pattern and the third records the image pattern. The slits were about 500 nm wide and the grating had a period of about 1000 nm.
This experiment was then repeated with a fullerene compound containing 60 carbon and 48 fluorine atoms.