Jump to main content
Jump to site search

Issue 11, 2014
Previous Article Next Article

Characterization of biofluids prepared by sessile drop formation

Author affiliations


Sessile drop formation, also called drop deposition, has been studied as a potential medical diagnostic, but the effects of complex biofluid rheology on the final deposition pattern are not well understood. We studied two model biofluids, blood plasma and synovial fluid, when deposited onto slightly hydrophilic substrates forming a contact angle of 50–90°. Drops were imaged during the evaporation process and geometric properties of the drop, such as contact angle and drop height, were calculated from the images. The resulting dried biofluid drops were then examined using light microscopy and Raman spectroscopy to assess morphological and chemical composition of the dried drop. The effect of substrate contact angle (surface wetting) and fluid concentration was examined. We found that when biofluids are deposited onto slightly hydrophilic surfaces, with a contact angle of 50–90°, a ring-shaped deposit was formed. Analysis of the drying drop's geometric properties indicates that biofluid dynamics follow the piling model of drop formation, as proposed by Deegan et al. The final deposition pattern varied with substrate surface and concentration, as shown by light microscopy photos of dried drops. The chemical composition of the outer ring was minimally affected by substrate surface, but the spatial heterogeneity of protein distribution within the ring varied with concentration. These results indicate that biofluid drop deposition produces ring-shaped deposits which can be examined by multiple analytical techniques.

Graphical abstract: Characterization of biofluids prepared by sessile drop formation

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 Nov 2013, accepted on 21 Mar 2014 and first published on 21 Mar 2014

Article type: Paper
DOI: 10.1039/C3AN02175K
Author version
Download author version (PDF)
Analyst, 2014,139, 2734-2741

  •   Request permissions

    Characterization of biofluids prepared by sessile drop formation

    K. A. Esmonde-White, F. W. L. Esmonde-White, M. D. Morris and B. J. Roessler, Analyst, 2014, 139, 2734
    DOI: 10.1039/C3AN02175K

Search articles by author