Amperometric Detection of Plant Volatiles Using Metal Oxide Nanoparticles

Volatile organic compounds released by pathogen-infected plants can be used as fingerprints for plant disease detection via electronic nose technologies^1,2. In this work, nanoparticles of TiO₂ or SnO₂ modified on screen-printed carbon (SP) electrodes have been developed for detection of fruit volatiles using amperometric techniques. p-ethylguaiacol, is a characteristic compound present in the volatile signature of  fruits infected with a pathogenic fungus called Phytophthora cactorum. The electroanalytical data obtained using cyclic voltammetry and differential pulse voltammetry showed that both SnO₂ and TiO₂ exhibited high sensitivity (174–188 mA cm^-2 mM^-1) and low detection limits (35–62 nM) for p-ethylguaiacol detection³. Both biosensors were evaluated for interference by adding common green leaf volatiles (cis-3-hexel-1-ol, hexyl acetate and cis-3-hexen-1-yl acetate). The results demonstrate that both metal oxides are a reasonable alternative to expensive electrode materials such as gold or platinum for amperometric sensor applications.

Reference

1. T. Baldwin, A. Kessler and R. Halitschke, Curr. Opin. Plant Biol., 2002, 5, 351.
2. P. W. Par´e and J. H. Tumlinson, Plant Physiol., 1999, 121, 325.
3. Y. Fang, Y. Umasankar and R. P. Ramasamy, Analyst., 2014, 139, 3804