Adsorption Studies of Fibrin Proteins onto Au- and Ag-Nanoparticles

Au- and Ag-nanoparticles were synthesized and conjugated with fibrin protein samples through a sodium citrate-induced method for possible 'AuNPs+fibrin' and 'AgNPs+fibrin' corona formation adsorption studies. Average spherical diameter sizes of 11, 18, 45, and 50 nm of Au-nanoparticles and 12, 14, and 26 nm of Ag-nanoparticles were considered for the conjugation process. The possible formation of 'AuNPs+fibrin' and 'AgNPS+fibrin' coronas through adsorption of fibrin protein molecules onto Au- and Ag-nanoparticles was verified using UV-vis and FTIR spectroscopies, ζ-potential, and TEM imaging. UV-vis red shift was observed on fibrin-conjugated AuNPs+fibrin/AgNPs+fibrin coronas relative to the unconjugated Au-/Ag-nanoparticles. FTIR spectra provided traces of possible fibrin functional atoms' bonding with Au- and Ag-nanoparticle surface atoms. TEM imaging was also utilized to observe and estimate nanoparticle distribution and sizes. A different nature of conjugation mechanism was noted on Au-/Ag-nanoparticles and fibrin protein molecules. Unconjugated Au-nanoparticles materialize as agglomerates of nanoclusters, while fibrin-conjugated AuNPs+fibrin coronas appear as dispersed individual random nanoparticles. On the other hand, unconjugated Ag-nanoparticles occur as scattered irregular individual nanoparticles that agglomerate into AgNPs+fibrin corona nanoclusters upon conjugation with fibrin protein molecules. Conjugated fibrin proteins do not lose their conformational structure or functional property.