Fast Dynamic Visualizations in Microfluidics Enabled by Fluorescent Carbon Nanodots

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 13; no. 34
• Main Authors: Huang, Yi, Xiao, Lian, An, Tingting, Lim, Wenxiang, Wong, Teckneng, Sun, Handong
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-09-2017
• Subjects: Biomedical materials; Carbon; carbon nanodots; Chemical reactions; droplets; Drug delivery systems; flow visualization; Fluid dynamics; Fluid flow; Fluorescence; Frames per second; interfaces; Microfluidics; Microparticles; Nanotechnology; Particle physics; Visualization; carbon nanodots; interfaces; droplets; flow visualization; microfluidics
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201700869

Microfluidic systems have become a superior platform for explorations of fascinating fluidic physics at microscale as well as applications in biomedical devices, chemical reactions, drug delivery, etc. Exploitations of this platform are built upon the fundamental techniques of flow visualizations. However, the currently employed fluorescent materials for microfluidic visualization are far from satisfaction, which severely hinders their widespread applications. Here fluorescent carbon nanodots are documented as a game‐changer, applicable in versatile fluidic environment for the visualization in microfluidics with unprecedented advantages. One of the fastest fluorescent imaging speeds up to 2500 frames per second under a normal contionous wave (CW) laser line is achieved by adopting carbon nanodots in microfluidics. Besides better visualizations of the fluid or interface, fluorescent carbon nanodots‐based microparticles enable quantitative studies of high speed dynamics in fluids at microscale with a more than 90% lower cost, which is inaccessible by traditionally adopted fluorescent dye based seeding particles. The findings hold profound influences to microfluidic investigations and may even lead to revolutionary changes to the relevant industries.
Fluorescent carbon nanodots (CDs) are documented as a game‐changer for the flow visualization of mixing, microfluidic droplets, etc. For the first time, this study synthesizes and introduces CDs microsized seeding particles for quantitative measurements of flow fields at microscale. Overall, it is demonstrated that fluorescent CDs can serve as an advantageous and affordable material for visualization in microfluidics.