l-Cysteine Graphene Oxide Deposition on Contact Lenses.

Objective: l-cysteine graphene oxide (CysGO) was synthesized and deposited onto the hydrogel and silicone hydrogel contact lenses (CLs) to study the surface characterization.

Methods: A cysteine graphene oxide composite was synthesized, characterized, and deposited on commercially available soft CLs. Characterization techniques such as FESEM, Fourier Transform Infrared, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Ultraviolet-Visible spectroscopy were employed to analyze CysGO deposited lens surface characterisation. Swelling and transmission percentages were calculated.

Results: Raman spectra revealed an increased Id/Ig ratio of 2.5 for CysGO compared with GO (2.25), indicating reduced layer stacking due to cysteine interaction. IR spectra confirmed the presence of amide groups, and XPS spectra exhibited a distinct s2p peak at 164eV and N2 spectrum at 399 eV exclusively in CysGO, confirming its deposition on the lens substrate. The deposited CLs showed a uniform coating of CysGO, an increase in the swelling percentage (P<0.001), and no difference in transmittance percentage when compared with the control.

Conclusion: This study presents the inaugural investigation of CysGO deposition applied to CL, revealing its advantageous properties, including uniformity and enhanced wettability. The potential of this coating extends beyond these characteristics, prompting further exploration of its diverse properties and applications in subsequent studies.