ASSIS, O. B. G. de

CORREA, D. S.

MATTOSO, L. H. C.

OLIVEIRA JR, O. N.

RODRIGUES, S. E. B.

SHIMIZU, F. M.

Portuguese

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Using an e-tongue based on impedancespectroscopy to detect E. ColiFlávio Makoto Shimizu1,2, Stanley Endrigo Bilatto Rodrigues3,1, Daniel SouzaCorrêa1, Odilio B. G. Assis1, Luiz Henrique Capparelli Mattoso1, Osvaldo NovaisOliveira Jr21Embrapa Instrumentação Agropecuária - São Carlos, 2Instituto de Física de SãoCarlos/USP, 3Universidade Federal de São Carlos - Campus: São Carlose-mail: flamakoto@yahoo.com.brFood contamination by bacteria is still a serious public health problem, which hasmotivated research on the development of low-cost devices capable of real timeresponse to detect contamination at an initial stage. Most of the contributions inthe literature, however, involve biosensors employing complex, time-consumingmethodologies requiring high cost equipment. In this study, we developed anelectronic tongue (e-tongue) for detecting Escherichia Coli (E. Coli) in which thesensing units comprise pepsin, lysozyme and trypsin enzymes and poly(allylaminehydrochloride) (PAH) polyelectrolytes in layer-by-layer (LbL) films. The optimizedconditions  for  adsorption  of  the  various  layers  were  determined  frominvestigation  of  the  kinetics  of  adsorption  for  the  enzymes,  while  UV-Visabsorption spectroscopy and atomic force microscopy were used to monitor filmgrowth. Distinct nanostructured layer architectures were deposited onto platinuminterdigitated electrodes to measure with impedance spectroscopy the electricalresponse for the medium containing E. Coli bacteria. Capacitance and tan δ datawere used for statistical  analysis using visualization methods within the PEx-Sensors  software.  The  results  indicate  that  the  e-tongue  is  able  to  clearlydiscriminate between non-contaminated and contaminated samples with bacteria,in the range from 103 to 107 CFU.We thank the FAPESP, CNPq, CAPES, and nBioNet network for financial support.Acknowledgments are also given to Angelo L. Gobbi and Maria H. O. Piazzetta foruse of the microfabrication laboratory (LMF/LNNano-LNLS).1380XIV Brazil MRS Meeting - Rio de Janeiro, from 27 September to 01 October, 2015

Using an e-tongue based on impedance spectroscopy to detect E. Coli.

http://www.alice.cnptia.embrapa.br/bitstream/doc/1036647/1/UsinganetonguebasedonimpedancespectroscopytodetectE.Coli.pdf

Using an e-tongue based on impedance spectroscopy to detect E. Coli.

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