IGM Colloquium: Single-molecule imaging and photodetection with nanomechanical resonators at room temperature
Absorption microscopy is a powerful technique, enabling the detection of single non-fluorescent molecules at room temperature. We show that nanomechanical photothermal sensing surpasses the shot-noise-limited sensitivity of state-of-the-art optical absorption techniques by more than two orders of magnitude. Using stress-optimized silicon nitride resonators, we achieve femtowatt-sensitivities at room temperature. Such a sensitivity not only results in unprecedented signal-to-noise ratios for the imaging of single molecules, but it is on a par with the sensitivity of liquid helium cooled IR/THz photodetectors. Room temperature nanomechanical photothermal sensors hence present a competitive alternative to i) established imaging tools, such as electron or optical microscopy, and ii) cooled broadband IR/THz photodetectors.