Enhanced Biosensing of Bisphenol A Using a Nanointerface Based on Tyrosinase/Reduced Graphene Oxides Functionalized with Ionic Liquid

Reduced graphene oxide (rGO) nanosheets functionalized with 1,3-di(4-amino-1-pyridinium) propane tetrafluoroborate ionic liquid (DAPPT) was successfully synthesized and fully characterized. DAPPT-rGO nanosheets were coated to a glassy carbon electrode (GCE) surface to immobilize tyrosinase (Tyr). The Tyr-DAPPT-rGO/GCE was characterized with scanning electronic microscopy and electrochemical impedance spectroscopy. The biosensor shows a linear response to bisphenol A (BPA) in the concentration range of 1.0×10 −9 ∼3.8×10 −5 mol L −1 . The detection limit was calculated to be 3.5×10 −10 mol L −1 (S/N=3). The practical application was demonstrated by determining BPA leaching from commercial plastic drinking bottles.