Dispersion Of Purified Single Wall Carbon Nanotube In Polyethylene Glycol And Polypyrrole For An Improved Efficiency Of A Glucose Biosensor

Single wall carbon nanotubes (SWCNTs) are a class of materials that have been utilized in the field of sensors, drug delivery, bioimaging etc. SWCNTs have been used in the field of sensors because of their aspect ratio and the network they form for a faster electron transfer. The presence of impurities such as transition metals, amorphous carbon and structural defects hinders the process of electron transfer. The purification of SWCNTs thus becomes necessary for such applications. Here we present the purification process of SWCNTs that does not damage the tubes or shorten the tubes. These purified SWCNTs are later dispersed in polyethylene glycol (PEG) and pyrrole (Py) at a concentration of 1mg/ml and later coated onto a glassy carbon electrode (GCE) for the detection of glucose. The GCE/SWCNTs was coated with glucose oxidase (3mg/ml) and dried at room temperature for 90 min and glucose is amperometrically detected in 0.05M PBS at 0.7V versus Ag/AgCl. The GCE/SWCNT/PEG gave a detection limit of 0.434 µM and a current sensitivity of (0.08164± 0.001129 µA mM ‐1 , r 2 =0.9975). The GCE/SWCNT/Py gave a detection limit of 0.9617µM with a sensitivity of (0.04189± 0.00087 µA mM ‐1 , r 2 =0.9944). These results prove that purification of SWCNTs with a mild oxidative step does not hamper the electron transfer rate and the dispersion of SWCNTs obtained helps in the entrapment of glucose oxidase without needing an additional protective layer.