Photothermal DNA Release from Laser-Tweezed Individual Gold Nanomotors Driven by Photon Angular Momentum
Journal article, 2018

Gold nanoparticles offer a unique possibility for contact-free bioanalysis and actuation with high spatial resolution that increases their potential for bioapplications such as affinity-based biosensing, drug delivery, and cancer treatment. Here we demonstrate an ultrasensitive optomechanical method for probing and releasing DNA cargo from individual gold nanoparticles trapped and manipulated by laser tweezers. Single nanorods are operated as rotational nanomotors, driven and controlled by circularly polarized laser light in aqueous solution. By rotational dynamics analysis, we resolve differences in the thickness of adsorbed ultrathin molecular layers, including different DNA conformations, with nanometer resolution. We then utilize photothermal heating to release DNA from single nanomotors while measuring the temperature-dependent kinetics and activation energy of the DNA melting process. The method opens new possibilities for optomechanical quantification and application of thermally induced molecular transitions in strongly confined geometries, such as inside microfluidic devices and single cells.


Hana Sipova

Chalmers, Physics, Bionanophotonics

Lei Shao

Chalmers, Physics, Bionanophotonics

Nils Odebo Länk

Chalmers, Physics, Bionanophotonics

Daniel Andrén

Chalmers, Physics, Bionanophotonics

Mikael Käll

Chalmers, Physics, Bionanophotonics

ACS Photonics

2330-4022 (eISSN)

Vol. 5 6 2168-2175

Subject Categories

Physical Chemistry

Atom and Molecular Physics and Optics

Other Physics Topics



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