Characterization of biofluids prepared by sessile drop formation

Area of Science:

• Biophysics
• Materials Science
• Analytical Chemistry

Background:

• Sessile drop deposition is a potential medical diagnostic tool.
• The influence of complex biofluid rheology on deposition patterns is not well understood.

Purpose of the Study:

• To investigate the effects of biofluid rheology on drop deposition patterns.
• To analyze the impact of substrate wetting and fluid concentration on deposit morphology and composition.

Main Methods:

• Studied model biofluids (blood plasma, synovial fluid) on hydrophilic substrates (contact angle 50-90°).
• Imaged drops during evaporation to calculate geometric properties.
• Examined dried drops using light microscopy and Raman spectroscopy for morphology and chemical analysis.

Main Results:

• Biofluid drops formed ring-shaped deposits on slightly hydrophilic surfaces.
• Drying dynamics followed the piling model of drop formation.
• Deposition patterns varied with substrate surface and concentration; protein distribution heterogeneity increased with concentration.

Conclusions:

• Biofluid drop deposition yields reproducible ring-shaped deposits.
• Substrate properties and concentration significantly impact deposit morphology and chemical heterogeneity.
• These findings support the use of biofluid drop deposition for analytical techniques.