Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

A microscale-molecular weight sensor: probing molecular diffusion between adjacent laminar flows by refractive index

Colin D Costin1, Robert E Synovec

  • 1Center for Process Analytical Chemistry, Department of Chemistry, University of Washington, Seattle 98195-1700, USA.

Analytical Chemistry
|September 19, 2002
PubMed
Summary

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Optimizing chemical information retrieval from in-field proton transfer reaction time-of-flight mass spectrometry breath analysis to discover compounds correlated to tetrachloroethylene concentration.

Talanta·2026
Same author

Workflow for characterizing volatile oxidation compounds in walnut oil by headspace solid-phase microextraction comprehensive two-dimensional gas chromatography time of flight mass spectrometry coupled with tile-based Fisher ratio analysis and other chemometric tools.

Journal of chromatography. A·2026
Same author

Adapting Tile-Based Discovery Analysis for Comprehensive Two-Dimensional Gas Chromatography with Vacuum Ultraviolet Spectroscopy Data of Gas Oils.

Analytical chemistry·2026
Same author

Developing 2D mzCompare for single comprehensive two-dimensional chromatography time-of-flight mass spectrometry chromatograms: Substantial resolution enhancement in the context of statistical overlap theory.

Journal of chromatography. A·2026
Same author

Tile-Based Fisher Ratio Analysis with Support Vector Machine Regression Modeling of GC×GC-TOFMS Data of VOCs Produced by <i>Malassezia pachydermatis</i> Grown at Variable pHs.

Analytical chemistry·2025
Same author

Optimizing retention time and peak width reproducibility with high peak capacity in high-speed gas chromatography using dynamic pressure gradient injection.

Journal of chromatography. A·2025

This study introduces a microfluidic device that measures molecular weight by analyzing laser beam deflection caused by diffusion between fluid streams. The sensor accurately determines molecular weight for poly(ethylene glycol) and has potential for DNA and proteins.

Area of Science:

  • Analytical Chemistry
  • Microfluidics
  • Physical Chemistry

Background:

  • Molecular transport in microfluidic devices primarily occurs via diffusion in laminar flows.
  • Accurate molecular weight determination is crucial for analyzing various chemical and biological systems.

Purpose of the Study:

  • To develop a microscale sensor for determining analyte molecular weight using refractive index gradient (RIG) detection.
  • To evaluate the sensor's performance for poly(ethylene glycol) (PEG) over a wide molar mass range.

Main Methods:

  • A diode laser beam measures the refractive index gradient (RIG) between adjacent laminar flows in a microchannel.
  • Laser beam deflection is monitored at two positions to quantify diffusion.
  • The ratio of signals correlates to the analyte diffusion coefficient and molecular weight.

Related Experiment Videos

Main Results:

  • The microfluidic sensor successfully determined molecular weights of poly(ethylene glycol) (PEG) from 960 to 22,800 g/mol.
  • The measurement was independent of PEG concentration.
  • A limit of detection of 56 ppm for 11,840 g/mol PEG was achieved.

Conclusions:

  • The developed RIG-based microfluidic device offers a universal detection method for molecular weight determination.
  • This technique eliminates the need for analyte derivatization, making it suitable for real-time monitoring.
  • The sensor shows potential applicability for analyzing compounds like DNA and proteins in microfluidic systems.