Micro sensing of pH levels in biological samples by graphene-based Raman spectroscopy

Graphene provides a unique way for sensing local pH level of substances on micrometric scale, with important implications for the monitoring of cellular metabolic activities where protonic excretion could occur. Doping modifications of graphene, induced by the contact of the graphene with different pH solutions were investigated by micro-Raman spectroscopy in order to develop a pH biosensor. To test the developed biosensor with real biological systems, the pH values of cell culture media in different conditions were evaluated.