proteinadsorption

Protein adsorption is the adhesion of proteins from a solution to solid surfaces, forming a surface-bound layer that depends on both the protein and the substrate.

Driving forces include electrostatic interactions, hydrophobic effects, van der Waals forces, and, in some cases, covalent or specific binding.

Factors such as pH relative to the protein isoelectric point, ionic strength, temperature, protein concentration, and surface properties (chemistry, roughness, porosity) govern the extent and rate of adsorption.

Adsorption can be described by isotherms such as Langmuir or Freundlich and may follow pseudo-first-order or pseudo-second-order kinetics; diffusion to the surface often limits the rate.

Consequences include the formation of a protein corona on nanoparticles, fouling of biomedical implants, and possible conformational changes that alter activity or trigger immune responses.

Applications span biotechnology and medicine, including protein purification by affinity methods, biosensors, and controlling the biocompatibility of medical devices.

Characterization methods include quartz crystal microbalance with dissipation monitoring (QCM-D), surface plasmon resonance (SPR), ellipsometry, X-ray photoelectron spectroscopy (XPS), FTIR, and atomic force microscopy (AFM).

Common examples are adsorption of albumin on hydrophobic polymers, fibrinogen on metal surfaces, and enzymes on silica or polymer substrates.