Unprecedented plasmon-induced nitroxide-mediated polymerization (PI-NMP): a method for preparation of functional surfaces

A plasmon as a stimulus opens up new opportunities for selective and regulated “from-surface” polymerization and functionalization of surfaces. Here, the first example of plasmon-assisted nitroxide-mediated polymerization (NMP) of stimuli-responsive block copolymers poly(N-isopropylacrylamide)-co-4-vinylboronic acid is reported. The growth of a polymer film at room temperature was achieved via plasmon-induced homolysis of alkoxyamines covalently attached to the surface of plasmon-active gold gratings at room temperature. Control of temperature, finite-difference time-domain method simulation of plasmon intensity distribution shift during polymerization, electron paramagnetic resonance experiments and other assays provide strong support for the plasmon-initiated mechanism of NMP. We demonstrated not only the control of the resulting polymer thickness but also the preparation of a surface-enhanced Raman spectroscopy chip for the detection of glycoproteins as a powerful example of plasmon-assisted NMP potential.