Nanorod-aggregated flower-like CuO grown on a carbon fiber fabric for a super high sensitive non-enzymatic glucose sensor

Abstract

A novel and exceptionally sensitive glucose biosensor based on nanorod-aggregated flower-like CuO grown on a carbon fiber fabric (CFF) is developed for glucose detection, which is prepared by a simple, fast and green hydrothermal method. The electron transfer resistance of the CuO/CFF electrode on the interface between the electrode and the electrolyte is as low as 12.79 Ω as evaluated by electrochemical impedance spectroscopy. A cyclic voltammetry study reveals that the CuO/CFF electrode displays an excellent electrocatalytic activity toward the direct oxidation of glucose. Besides, chronoamperometry demonstrates a high sensitivity of 6476.0 μA mM⁻¹ cm⁻² at an applied potential of 0.45 V (vs. Ag/AgCl), with a fast response time and a low detection limit of only 1.3 s and ∼0.27 μM, respectively. In addition, the glucose sensor has high reproducibility with a relative standard deviation (R.S.D.) of 1.53% over eight identically fabricated electrodes and long-term stability with a minimal sensitivity loss of ∼9.9% over a period of one month as well as excellent anti-interference ability. Importantly, the CuO–CFF composite has such good flexible characteristics and can be fabricated into flexible electrodes for application in various complicated circumstances. This work presents a new strategy to achieve highly sensitive glucose sensors with flexibility by growing glucose electroactive nanostructure materials directly on multichannels and highly conductive carbon fiber fabrics.