An Active Surface Preservation Strategy for the Rational Development of Carbon Dots as pH-Responsive Fluorescent Nanosensors

Here we report the rational development of a carbon dot (CDs)-based fluorescent pH nanosensor by employing an active surface preservation strategy. More specifically, citric acid, urea and fluorescein were subjected to one-pot hydrothermal treatment, which preserved fluorescein-like structures on CDs. The obtained CDs showed pH-sensitive green emission, can be used determine variations from 3.7 12.1 fluorescence enhancement. Moreover, nanoparticles excellent selectivity toward pH, reversibility in different values, photostability, while being compatible with human cell lines (even at high concentrations). Furthermore, their performance as sensors was comparable reference determination procedures. Thus, strategy successfully employed develop nanosensors manner without post-synthesis functionalization strategies, show potential for future use determination.