
3-Mercaptopropyltrimethoxysilane Self Assembled Monolayers
3-Mercaptopropyltrimethoxysilane, commonly abbreviated as MPTS, is an organosilane compound that is used to form self assembled monolayers on surfaces. MPTS self assembled monolayers can modify surfaces with functional thiol groups, allowing for further chemical reactions and binding of biomolecules. MPTS is widely used in biosensing, corrosion inhibition, and nanofabrication applications.
How MPTS Self Assembled Monolayers Form
MPTS self assembled monolayers form via the hydrolysis and condensation of the trimethoxy groups on the MPTS molecules. When a surface like glass, silicon or metal is submerged in a dilute MPTS solution, the hydrolyzed MPTS molecules orient themselves in a closely packed, ordered arrangement on the surface. The thiol groups then bond strongly to the surface via chemisorption, anchoring the MPTS layer. The resulting monolayer has a surface coverage of thiol groups and methoxy groups.
Applications and Uses of MPTS Monolayers
Some applications of MPTS self assembled monolayers include:
• Biosensing – The thiol groups allow for attachment of biomolecules like proteins and DNA, used in biosensors and diagnostic assays.
• Corrosion inhibition – The monolayer acts as a barrier to prevent corrosion of metals like gold, copper, silver and iron.
• Nanofabrication – The molecules can be patterned using microcontact printing or photolithography, used to produce nanostructures.
• Surface modification – The surface properties like wettability, adhesion and friction can be altered by modifying the terminal groups.
The ordered structure, stability and variety of functional groups achievable with MPTS self assembled monolayers make them useful for a wide range of applications in nanotechnology, biomedical devices and surface chemistry.

