Carbon Nanotube/Green Tea Composite for the Electronic

Single-walled carbon nanotubes (SWNTs) and their composites are ideal candidates for chemical and biological sensing application, due to their unique electronic, chemical and physical properties. Green tea, or more specifically its main antioxidant component, epigallocatechin gallate (EGCG), has been found to disperse SWNTs in water and form SWNT/green tea (SWNT/EGCG) composite. With the presence of EGCG, this SWNT composite should have strong antioxidant properties and thus respond to reactive oxygen species (ROS). Here we report the fabrication and characterization of a SWNT/Green Tea (SWNT/EGCG) sensing system for the detection of H2O2 in solution phase. By liquid-gating field-effect (FET) transistor measurements and conductance measurements, it was observed that the conductance of SWNT/EGCG composite thin film increased with increase in H2O2 concentrations. These findings suggest that SWNT/Green Tea composite has a great potential for developing simple resistivity-based nanoscale sensors for the electronic detection of ROS.