XII Iberian Meeting of Electrochemistry XVI Meeting of the ...

XII Iberian Meeting of Electrochemistry & XVI Meeting of the Portuguese Electrochemical Society O B 05
Polymeric chemiresitive sensors for wood classification
Renata Lippi, Jonas Gruber, Juliana R. Cordeiro, Erica S. Takahashi,
Rosamaria W. C. Li
Instituto de Química, Universidade de São Paulo, SP, Brasil
Renata.Lippi@poli.usp.br
An electronic nose [1] capable of identifying two pairs of wood species: (a) mahogany
and cedar (Figure 1) and (b) Brazilian walnut and black-cinnamon was developed. The
electronic nose consists of four gas sensors, fabricated by the deposition of thin doped
conjugated polymer films onto the surface of interdigitated electrodes. The electrical
conductance of these electrodes was measured during exposure to the volatile
compounds of wood samples. Treatment of these data by principal component analysis
and by cluster analysis gave excellent separation between the data sets. Leave-one-out
analysis [2] presented a rate of hits of 100% in 80 identification assays carried out
randomly with the above-cited species. Sets of electrodes have been tested for over six
months and are still operational. The cost of each electrode is less than US$ 10. The
equipment is portable and has low power consumption; hence, it can be used by police
officers on the roads for the inspection of lorries carrying woods.
Figure 1. PCA plot for mahogany and cedar
Acknowledgments: to CNPq for the grants and financial support.
References
[1] Gardner, J. W.; Bartlett, P. N. Electronic Noses Principles and Applications, 1999, Oxford
University Press. N.Y.
[2] Lopes, F. M.; Martins-Jr, D. C.; Cesar-Jr, R. M. BMC Bioinformatics, 2008, 9, 451.
September, 811, 2010. ISEL - Lisbon 38