Enzyme from Banana (<i>Musa</i> sp.) Extraction Procedures for Sensitive Adrenaline Biosensor Construction

Abstract

For building a biosensor, at least two enzyme sources can be employed. The pure enzyme has features with better selec tivity and low stability. Crude extract presents better stability and wrong selectivity. Thus, one intermediate condition can be feasible joining both benefits of crude extract and pure enzymes. For that result, several procedures of extraction and semi purification of polyphenol oxidase (PPO) enzyme from banana ( Musa sp.) were studied. The results showed that cleaned enzymatic extracts presented higher specific activities than crude extracts (2.8 up to 5.3 fold), despite the total protein concentration diminishing from 27% up to 72%, indicating that polyphenol oxidase (PPO) enzyme was preserved in them. The biosensors with 125 AU mL - 1 containing cleaned enzymatic extracts performed better by grind ing or grinding plus sonication for 30 s. They were linear over the ranges of 5.9 × 10 - 6 mol ·L - 1 to 1.4 × 10 - 3 mol·L - 1 and 7.9 × 10 - 8 mol·L - 1 to 4.0 × 10 - 3 mol·L - 1 , respectively. The limit of Detection (LOD) was 5.9 × 10 - 6 mol·L - 1 and 7.9 × 10 - 8 mol·L - 1 , respectively. The LOD obtained is adequate to adrenaline determination on blood and medicinal sam ples, and were applied in medicinal samples with satisfactory results.