Products | SPR Sensor chips | Data sheets

C-type sensor chips

XanTec’s C-type sensor chips are based on a synthetic 3D hydrogel matrix composed of linear aliphatic polycarboxylate chains with very high charge density, grafted onto a hydrophilic adhesion promoter on a gold support. Ligands can be covalently attached via their amine, thiol, or aldehyde groups using established coupling chemistries such as EDC/NHS activation, thiol–maleimide conjugation, or reductive amination. This enables immobilization of proteins, antibodies, peptides, nucleic acids, and small molecules.

The exceptionally high charge density renders the surface susceptible to nonspecific binding of cationic biomolecules; however, the aliphatic polymer backbone provides outstanding chemical robustness. This makes C-type coatings particularly well suited for demanding chemical environments and for non-biological applications that require a dense and chemically well-defined carboxylate (COOH) surface, such as solid-phase syntheses or the preparation of metal–organic frameworks (MOFs).

Key features:

Schematic illustration of a 3D C-type sensor chip. Red dots represent negatively charged carboxyl groups distributed along the grey polymer chains. The decaying red gradient represents the evanescent field.1
Product code C30M C80M C150D
Base coating 3D, 30 nm aliphatic polycarboxylate
(medium density)
3D, 80 nm aliphatic polycarboxylate
(medium density)
3D, 150 nm aliphatic polycarboxylate
(high density)
Electrostatic preconcentration capacity [µRIU]2 ≈ 9,000 ≈ 23,000 ≈ 50,000
Recommended ligands
  • proteins
  • peptides
  • carbohydrates
  • nucleic acids (spot immobilization)
Recommended analytes
  • proteins
  • peptides
  • nucleic acids
  • carbohydrates
  • proteins
  • peptides
  • nucleic acids
  • carbohydrates
  • peptides
  • small molecules
  • fragments
  • small carbohydrates
Intended purpose
  • spot immobilization of ligands requiring high chemical robustness (e.g. amino-modified DNA oligonucleotides)
  • non-biological applications requiring a dense and well-defined carboxylate (COOH) surface

1 All illustrations are schematic representations and are not drawn to scale; dimensions, densities, and spatial relationships do not reflect actual physical or chemical proportions.

2 Preconcentration capacity determined by injecting 100 µg/mL bovine serum albumin (BSA) in 5 mM sodium acetate pH 5.0, with 1 µRIU corresponding approximately to 1 RU. Maximum covalent coupling yields depend on ligand properties and typically range from approximately 25–45% of the respective electrostatic preconcentration capacity.