Parallel differential mobility analysis for electrostatic characterization and manipulation of nanoparticles and...

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Biophysics

Background:

• Electrophoretic mobility of charged airborne nanoparticles (NPs) and macromolecules is crucial for their analysis and handling.
• Existing methods may not preserve the bioactivity of biological NPs during characterization and sampling.

Purpose of the Study:

• To develop and validate a novel technique for the characterization and size-defined sampling of airborne bio-NPs.
• To assess the preservation of bioactivity (e.g., enzyme activity) during NP analysis and sampling.
• To enable real-time measurement of NP size and surface properties.

Main Methods:

• Utilized a newly developed parallel differential mobility analyzer coupled with an electrostatic particle sampler.
• Employed a radioactive source (Po-210) for charge conditioning of nanoparticles.
• Performed real-time size measurements and determined the number of attached antibodies.

Main Results:

• The parallel differential mobility analyzer successfully characterized and sampled airborne bio-NPs, preserving their bioactivity.
• Charge conditioning using Po-210 enabled size-defined sampling, despite low yield for sub-20-nm particles.
• The technique allowed for real-time size determination of NPs and viruses, and quantification of antibody surface coverage.

Conclusions:

• The developed technique offers a powerful tool for the analysis and handling of airborne nanoparticles, particularly bio-NPs.
• It enables size-defined sampling and characterization while maintaining biological activity.
• This method provides valuable insights into NP surface properties, such as antibody coverage.