( PACCON 2018 ) pH-sensitive fluorescent carbon nanoparticles coated surface for visualization of highly effective antifouling activity based fluorescence “ ON / OFF ” phenomena

There are many reports about developing hydrophilic, zwitterionic materials, etc. to avoid contamination in biomedical devices. However, the traditional technique to evaluate antifouling effect of developed materials was limited at cell counting based SEM morphology. Taking advantage of pH-switchable fluorescent carbon-based nanoparticles (FNPs) along with the combination of fluorescent, colorimetric, and electrochemical signals generated from surfaces coated with FNPs, we have successfully developed fast and easy method for observance the performance of FNP-coated surfaces with mammalian cell and bacterial antifouling based fluorescent off/on system. The FNP-coated surfaces showed high sensitivity by switching reversibly hydrophilic-hydrophobic states of the zwitterionic component in a broad range of pH conditions, which showed excellent antifouling effect in acidic and basic environments and exhibited strong interaction with bacterial surface through fluorescence ON/OFF system. We deposited FNPs on a screen-printed carbon electrode (SPCE) for cyclic voltammetry (CV) analysis, causing a remarkable decrease in CV signals indicating the adherence of mammalian and bacterial cells onto coated surfaces. In conclusion, a pH-switchable zwitterionic FNP-coated surface is introduced as a rapid and efficient method for detection and control of biological adhesion of cells and bacteria onto diverse surfaces according to fluorescent on/off behavior and electrochemical signals.