Electrochemical detection of uric acid using ruthenium-dioxide-coated carbon nanotube directly grown onto Si wafer

摘要

Carbon nanotubes (CNTs) directly grown onto a Si substrate by thermal chemical vapor deposition were used in uric acid (UA) detection. The process is simple and formation is easy without the need for additional chemical treatments. However, CNTs lack selectivity and sensitivity to UA. To enhance the electrochemical analysis, ruthenium oxide was used as a catalytic mediator in the modification of electrodes. The electrochemical results show that RuO2 nanostructures coated onto CNTs can strengthen the UA signal. The peak currents of RuO2 nanostructures coated onto CNTs linearly increase with increasing UA concentration, meaning that they can work as electrodes for UA detection. The lowest detection limit and highest sensitivity were 55nM and 4.36 mu A/mu M, respectively. Moreover, the characteristics of RuO2 nanostructures coated onto CNTs were examined by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. (C) 2015 The Japan Society of Applied Physics