Oxide derived Cu nanofibril assembly for enhanced nonenzymatic glucose sensing

In this report, we have prepared copper nanofibril assembly via thermal oxidation followed by electrochemical reduction processes, exhibiting superior glucose detection ability. The morphological analysis evidenced the formation of rough islands or nanofibril structure on the Cu surface depending on initial thermal oxidation temperature. The glucose detection performance was investigated by performing cyclic voltammetry and chro-noamperometry with varying glucose concentration. A high sensitivity (4131.57 & mu;A mM-1 cm-2), low detection limit (1.41 & mu;M), wider linear range (0-3.9 mM) and long-term stability (30 days) have been recorded for electrode thermally oxidized at 400 degrees C followed by electrochemical reduction process (rCu_400). The sensitivity is almost three times higher in comparison to the planner Cu surface. This significantly enhanced glucose sensing ability rCu_400 has been attributed to the nanofibril morphology, origination of Cu (111) facet and formation of a stable oxide layer evidenced by scanning electron microscopy, X-ray diffraction and energy dispersive spec-troscopy analysis. Despite higher sensitivity, rCu_400 electrode does not show any response to the chloride ion, dopamine, ascorbic acid and uric acid. These results indicate that the Cu nanofibril structure prepared via simple oxidation/reduction process can be an excellent candidate to be used as an electrode for glucose sensing application.

Automated summary

In this study, we prepared a copper nanofibril assembly using thermal oxidation and electrochemical reduction processes. The resulting structure exhibited excellent glucose detection ability with a high sensitivity, low detection limit, wider linear range, and long-term stability. The enhanced glucose sensing ability of the copper nanofibril structure can be attributed to its morphology, origin of the Cu (111) facet, and formation of a stable oxide layer. This structure showed no response to other interfering substances such as chloride ion, dopamine, ascorbic acid, and uric acid, making it a promising candidate for glucose sensing applications.