Thiolmodified

Thiolmodified is a descriptor used in chemistry to denote a molecule or material that has been chemically modified to bear one or more thiol groups (-SH). The thiol functionality is highly reactive and versatile, enabling covalent attachment to metals, particularly gold, as well as participation in disulfide exchange, thioether formation, and various bio-orthogonal conjugation chemistries such as maleimide-thiol coupling and thiol-ene reactions.

Thiol modification can be achieved by introducing thiol-bearing reagents to available functional groups (for example converting amines or carboxyls to thiols) or by incorporating cysteine residues into peptides and proteins, followed by conditions that reveal or preserve free thiol groups. In biomaterials and nanotechnology, thiol-modified ligands are routinely used to anchor molecules to gold surfaces or to construct thiol-based self-assembled monolayers.

Applications include immobilization of biomolecules on sensors and electrodes, assembly of thiolated DNA onto gold nanoparticles, and the fabrication of functional nanomaterials. The robust gold–thiol interaction underpins many biosensor platforms and nanoengineering strategies, while disulfide chemistry enables reversible conjugation and programmable release in reductive environments.

Thiol groups are prone to oxidation to disulfides and can be reactive to oxidants and air; therefore, handling often requires attention to storage and redox state. Characterization methods include spectroscopic techniques, mass spectrometry, and surface-sensitive tools such as X-ray photoelectron spectroscopy or ellipsometry when applied to surfaces.