Non-enzymatic electrochemical glucose sensors based on polyaniline/reduced-graphene-oxide nanocomposites functionalized with silver nanoparticles†
We demonstrate silver (Ag) nanoparticle decorated polyaniline (PANI) and reduced graphene oxide (rGO) as Ag–PANI/rGO nanocomposites to realize non-enzymatic glucose sensors. The Ag–PANI/rGO nanocomposite was synthesized by a simple electrochemical method at room temperature. The proposed Ag–PANI/rGO nanocomposite exhibited excellent electrochemical characteristics and sensing performance for use in electrochemical glucose sensors, as compared to bare PANI and PANI/rGO. We also investigate the underlying mechanisms for the nanocomposite formation of Ag, PANI and rGO by using various characterization techniques. The interactions between Ag species with N atoms of the PANI backbone boost the electron transfer rate during the electrochemical reduction of glucose. The calibration plot for the electrochemical response of Ag–PANI/rGO towards glucose was recorded for the range of 50 μM to 0.1 μM (R2 = 0.99) with a detection limit of 0.79 μM and a rapid response time of a few seconds. These results indicate the significant potential of Ag–PANI/rGO nanocomposites as non-enzymatic glucose sensors. We also demonstrate the feasibility of using Ag–PANI/rGO nanocomposites for the detection of glucose in real samples such as as-supplied organic fluids (orange juice, apple juice, mango juice, coke and milk). The amperometry technique was used to verify that a significant increase of the current response occurred along with a sensitive increase in the glucose concentration. We believe that this work can introduce an emerging concept of nanocomposites to realize simple and reliable electrochemical glucose sensor platforms.