Immobilization of alkyl-pterin photosensitizer on silicon surfaces through in situ S_N2 reaction as suitable approach for photodynamic inactivation of Staphylococcus aureus

Area of Science:

• Surface chemistry and materials science.
• Biomolecular functionalization and nanotechnology.

Background:

• Self-assembled monolayers (SAMs) enable surface tailoring by adsorbing molecular layers.
• Functionalization allows for in situ chemical reactions to incorporate new properties.

Purpose of the Study:

• To immobilize pterin moieties onto silicon substrates via SAMs.
• To investigate the properties and applications of pterin-functionalized surfaces.

Main Methods:

• Modification of silicon substrates with 11-bromoundecyltrichlorosilane.
• Nucleophilic substitution reaction to replace bromine groups with pterin (Ptr).
• Characterization using XPS, contact angle measurements, and AFM.

Main Results:

• Successful functionalization of silicon surface with O-undecyl-Ptr and N-undecyl-Ptr (1:8 ratio).
• Immobilized alkyl-pterins retained photochemical properties.
• Inhibition of Staphylococcus aureus growth under irradiation (84.3 ± 15.6% reduction).

Conclusions:

• Developed a method for creating photosensitive surfaces using SAMs and pterin.
• Demonstrated potential for microbiological self-cleaning properties on modified materials.
• Opened possibilities for functionalizing diverse materials like glass and metal.