Related Experiment Video
Updated: Jan 30, 2026

Nano-fEM: Protein Localization Using Photo-activated Localization Microscopy and Electron Microscopy
Published on: December 3, 2012
Photo-activated ultrasound localization imaging with laser-activated nanodroplets
Shensheng Zhao1,2,3, Junxi Yi2,3,4, Yueying Qiu1,2,3
1Department of Electrical and Computer Engineering, Grainger College of Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Abstract:
Super-resolution ultrasound localization (UL) imaging enables microvascular visualization beyond the acoustic diffraction limit, but is limited by the short circulation time and uneven distribution of microbubbles. Here, we present photo-activated UL (PaUL) imaging using laser-triggered nanodroplets for super-resolved imaging with precise spatiotemporal control. We synthesized dual-contrast indocyanine green (ICG)-encapsulated perfluoropentane nanodroplets and developed a programmable activation and imaging sequence. PaUL imaging achieved 21 µm spatial resolution and enabled on-demand contrast generation by tuning laser fluence. Compared to conventional UL imaging, PaUL imaging provided 2.4× faster vascular reconstruction and 1.6× longer tracking lengths in hemodynamic mapping. Its extended circulation time allowed up to 3× more localization events across imaging windows exceeding 20 minutes. Overall, PaUL imaging offers flexible, high-resolution contrast and can be integrated with photoacoustic imaging to enhance multimodal capabilities. This technique holds promise for microvascular imaging and image-guided therapeutic applications such as targeted drug delivery.
More Related Videos
11:00Photostimulation by Femtosecond Laser Activates Extracellular-signal-regulated Kinase ERK Signaling or Mitochondrial Events in Target Cells
Published on: July 6, 2019
11:57Whole-Brain 3D Activation and Functional Connectivity Mapping in Mice using Transcranial Functional Ultrasound Imaging
Published on: February 24, 2021
Related Concept Videos
Local Anesthetics: Chemistry and Structure-Activity Relationship
Co-activators and Co-repressors
tRNA Activation
Activation Energy
Eukaryotic Transcription Activators
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These...
Secondary Active Transport