Synthesis of Ta/Ni microcavity array film for highly sensitive uric acid detection

A novel Ta/Ni microcavity array film was successfully synthesized through monolayer polystyrene sphere template. That is, Ni bowl-like array film was first deposited into the template by electrochemical method. After dissolving the polystyrene spheres, Ta microcavity array film was deposited onto the Ni array by magnetron sputtering. Morphology observation revealed that the prepared Ta/Ni film was formed by a large number of bowl-like cavities with centre hole, which were arranged in hexagonal close-packed order. Combined with a gold layer sputtered on a glass substrate, this Ta/Ni microcavity array film can be used as an electrochemical electrode for the amperometric detection of uric acid. It exhibited a high sensitivity of 886 mu A.mM(-1)cm(-2), a detection limit of 0.1 mu M, and a wide linear range from 1 mu M to 1.4 mM. A possible mechanism was also given in the paper. The results demonstrate that the Ta/Ni microcavity array film is a promising new platform for the construction of non-enzymatic uric acid sensors.