Monday, April 29, 2013
Exhibit Hall
Biosensors are analytical tools responsible for combining the specificity of a bio-component active for a given analyte with the sensitivity of a transducer which converts the biological signal into an electrical signal, proportional to the concentration of the analyte and capable of detection. This enables getting quick answers and generating less waste for the environment. In this work, it was used as the bio-component commercial lipase type VII, derived from Candida rugosa - Sigma brand, both free and immobilized in glass beads. Its ability to hydrolyze triglycerides (esters) was used to detect the level of degradation of samples of soybean oil and biodiesel produced from this oilseed, at various concentrations, both of which are predominantly composed of esters. The hydrolysis products (fatty acids and H+ ions) result in potential variations, which were quantified using a pH electrode for non-aqueous solutions, used as a potentiometric transducer. In response time of 15 minutes, at pH 8.75 and 37°C, reproducibility of results were seen. There was also a significant potential difference in this range, proportional to the concentration of the samples, characteristic suitable for the construction of a biosensor. The results obtained in the study allowed to develop and validate a method based on the use of a potentiometric enzymatic biosensor, to be applied in monitoring the quality of soybean oil and biodiesel produced from soybean.
Acknowledgements: CNPq and FAPERJ for financial support.