Polymeric Layer-Mediated Redox Sensing System Containing Covalently Attached CdSe/ZnS Quantum Dots on Au Films

Reversible photoluminescence (PL) switching representsa highlydemanded feature in sensors, optical/electronic devices, imaging andlogic gates, etc. Utilizing a straightforward spin-coating-basedsample fabrication procedure, we developed a gold-quantum dot (QD)hybrid system that revealed PL switching in response to redox processes.The PL switching of the system relies on a redox-responsive poly[N-isopropylacrylamide-co-vinylferrocene-co-methacryloyl benzophenone] nanometric thick spacer layer,through which the QDs were attached to a gold film. The designed hybridsystem revealed a 2.3 & PLUSMN; 0.6-fold PL intensity switching factorarising from PL quenching upon oxidation of the spacer layer and PLrecovery after reducing the layer. Notably, the behavior was bothreversible and reproducible, judged by analysis of three samples andseveral applied redox processes. This study can open a window to furtherdevelopment of plasmonic-fluorophore switchable devices using stimuli-responsivepolymeric spacers in particular for sensing and bio-sensing applications.