Low-fouling properties in serum of carboxylic-oligo(ethylene glycol)-based interfaces

Author(s)

Santos, Adriano ^[1] ; Garcia Nicholson, Melany Isabel ^[1] ; Feliciano, Gustavo Troiano ^[1] ; Bueno, Paulo Roberto ^[1]

Affiliation

^[1] Univ Estadual Paulista, Inst Chem, Sao Paulo State Univ, BR-14800060 Araraquara, SP - Brazil

• Document type: Journal article
• Source: COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS; v. 618, JUN 5 2021.
• Web of Science Citations: 0

Abstract

In the present work we evaluated the low-fouling feature of a carboxylic-oligo(ethylene glycol) self-assembled monolayer (carboxylic-OEG-SAM) interface using a quartz crystal microbalance with dissipation monitoring (QCM-D). QCM-D measurements allowed us to estimate the amount of protein loading in two different serum dilutions at two different interfaces: bare gold and carboxylic-OEG. The observed amount of protein adsorbed onto bare gold is about twice higher that of carboxylic OEG interface, confirming the low-fouling characteristics of OEG-modified surfaces. Additionally, QCM-D results demonstrated the existence of two protein adsorption regimes, a faster and a slower, with distinct dissipation energies which was modelled by a two-step kinetic model. The faster regime was attributed to the adsorption of proteins into free sites of the carboxylic-OEG-SAM in a rigid binding process, followed by a slower and more viscoelastic adsorption process ascribed to structural conformational changes; this slower step conforms with the filling of remaining free sites associated with the steric hindrance in which protein-protein interactions defines the slower rate constant for the adsorption. (AU)

• FAPESP's process: 17/24839-0 - Nanoelectronics and nanoscale electrochemistry: fundaments and applications
• Grantee: Paulo Roberto Bueno
• Support Opportunities: Research Projects - Thematic Grants