Self-assembled microstructure of carbon nanotubes for enzymeless glucose sensor

Abstract

This work demonstrated the use of self-assembled thin films of multi-walled carbon nanotubes (CNTs) in designing enzymeless glucose sensor. Well-dispersed self-assembled CNT were prepared based on the spontaneous and strong chemisorption of polyoxometalates on CNT surface. Electrostatically self-assembled CNT films interlaced with cationic polyelectrolyte binding layer were constructed and used to confine the growth of copper (Cu) metal particles by the pulsed electrodeposition technique. The morphology of electroplated Cu on the CNT film was confirmed by scanning electron microscopy (SEM), and Cu were deposited as uniformly dispersed individual particles rather than continuous film on the CNT substrate. Sensing and assay performance of the copper deposits on CNT films to glucose were evaluated in detail. Cyclic voltammetry (CV), chronoamperometry ( I– t) and flow injection amperometry (FIA) revealed a high sensitivity, excellent stability, and good reproducibility in the glucose determination. The current response of the sensor reached 602.04 μA mM −1 cm −2 with enough high signal to noise ratios at various glucose concentration levels, which was superior than those of Cu electrodeposition on CNT reported so far. A detection limit of 1.0 × 10 −7 M (signal-to-noise = 3) and a linear range of 5.0 × 10 −7 to 1.8 × 10 −3 M were obtained. Present study provides a low cost and simply controlled test-bed for fundamental study on using self-assembled CNT films for sensor fabrication.