Intramolecular force

Nanoparticle

Biotechnology

Biology

Materials science

Nuclear physics

Biochemistry

Molecule

Stereochemistry

Polymer

In vivo

Physics

Nanotechnology

Organic chemistry

Molecular motor

Optics

Molecular machine

Photothermal therapy

Composite material

Excited state

Chemistry

Photoacoustic imaging in biomedicine

Energy landscape

Molecular imaging

Nature Communications

The exciting applications of molecular motion are still limited and are in urgent pursuit, although some fascinating concepts such as molecular motors and molecular machines have been proposed for years. Utilizing molecular motion in a nanoplatform for practical application has been scarcely explored due to some unconquered challenges such as how to achieve effective molecular motion in the aggregate state within nanoparticles. Here, we introduce a class of near infrared-absorbing organic molecules with intramolecular motion-induced photothermy inside nanoparticles, which enables most absorbed light energy to dissipate as heat. Such a property makes the nanoparticles a superior photoacoustic imaging agent compared to widely used methylene blue and semiconducting polymer nanoparticles and allow them for high-contrast photoacoustic imaging of tumours in live mice. This study not only provides a strategy for developing advanced photothermal/photoacoustic imaging nanoagents, but also enables molecular motion in a nanoplatform to find a way for practical application.

Highly efficient photothermal nanoagent achieved by harvesting energy via excited-state intramolecular motion within nanoparticles