Optical Fluorescent Biosensors: A Bright Nanotool for Early Detection in Biological Systems
supervised by Rachel Meallet, Gilles Clavier
Antibiotic-resistant bacteria and cancer are two of the most urgent health challenges, and thus, there is a push for early detection methods. For this purpose, optical biosensors utilizing fluorescent nanoparticles (FNPs) are a promising platform by offering biocompatibility, sensitivity, and facile surface functionalization. This PhD work presents a polymeric green fluorescent nanoparticle platform functionalized with a pH-sensitive red-emitting x-rhodamine fluorophore via click chemistry. The resulting ratiometric system (grafted particles – GPs) has increased fluorescence in acidic conditions with FRET possibly occurring between the two components. The GPs were investigated as potential optical biosensors for both prokaryotic cells (e.g., E. coli) and eukaryotic cells (e.g., cancerous cells and non-cancerous cells) based on the pH changes of their microenvironment. Together, these results demonstrate the GPs’ potential as a versatile platform for biological applications associated with pH changes.