X4C technology enables the development of next-generation In Vitro Diagnostic assays. Calix[4]arenes, that covalently attach to any surface, form well-defined, exceptionally stable, very thin and homogeneous monolayers, ready for post-functionalization with any biomolecule.

• X4C creates ultra-stable surfaces, resisting to low and high pH, etching conditions such as fluoride ions, high salt concentrations, high temperatures and drying, forming robust bioconjugates.
• X4C technology controls the density of functional groups at the surface, enabling the control of the number of biomolecules at the surface, for more sensitive and cost-effective assays.
• Calix[4]arenes coatings reduce the number of nanoparticles required for a test, cutting down the production costs of immunoassays.
• X4C technology can be applied to control the orientation of biomolecules, for enhanced applications.
• Calix[4]arenes can bind to any surface, of any shape and dimension, to produce any surface – biomolecule conjugate, opening the field of In Vitro Diagnostics to novel and innovative technologies.

Immunoturbidimetric assays are laboratory rapid, accurate and simple methods to determine the amount of an antigen in a sample by applying the principle of light-scattering measurements to antigen-antibody reaction. A specific category of immunoturbidimetry, called PETIA (Particle-Enhanced Turbidimetric ImmunoAssays), makes use of particles to increase the turbidity of the reaction, and so the signal and assay sensitivity. Plain particles or particle – antibody conjugates are used, depending on assay requirements.

X4C calix[4]arenes technology is perfectly adapted to modify latex and gold particles, providing the new materials with surface enhanced properties. Antibodies or other biomolecules can be immobilized covalently or passively to the newly modified particles, to generate highly performing conjugates.

Biosensors are analytical devices that use the combination of a sensitive biological element, e.g. cell receptors, enzymes, antibodies, nucleic acids, etc., and a detector element, working through optical, piezoelectric, electrochemical or electrochemiluminescence signals. The variety of biological molecules and detector principles gives rise to a plethora of different devices, relying on multiple surface – biomolecule constructs.

The versatility of calix[4]arenes, which have the capacity to covalently bind to any surfaces, makes them very attractive for the development of such biosensors. Germanium, silicon or gold surfaces can easily be coated with calix[4]arenes, to host biomolecules, such as antibodies, peptides, oligonucleotides or proteins.