Amperometric Bienzymic Sensor for Aspartame

Abstract

An amperometric enzyme electrode for the determination of aspartame was developed by covalent immobilization of alcohol oxidase and alpha-chymotrypsin. A platinum based hydrogen peroxide electrode was used as the detector. Excellent sensitivity was obtained using batch, flow-through and flow injection methods with detection limits of 2 x 10(-7), 4 x 10(-7) and 10(-6) mol l-1, respectively. Different strategies for eliminating interfering compounds, including the introduction of an additional alcohol oxidase-catalase membrane and signal subtraction using an alcohol electrode, were employed. A recovery study on seven food samples was carried out and the results were satisfactory.

Bienzymatic Biosensor for Rapid Detection of Aspartame by Flow Injection Analysis

“…Only few papers describe biosensors for the determination of aspartame in soft drinks. Those biosensors were based on the chemical co-immobilization of enzymes on different electrodes, such as ammonia-gas-sensing electrode [18], platinum-based hydrogen peroxide electrode [19], oxygen electrode [20], or graphite epoxy composite electrode [21]. Another strategy is based on the enzyme immobilization into columns integrated in flow systems: two enzyme columns containing peptidase and aspartate aminotransferase, respectively, immobilized on activated aminopropyl glass beads and an L-glutamate oxidase electrode [22] or another system consisting of a column containing pronase and an L-amino acid oxidase electrode [23].…”

Flow injection determinations of artificial sweeteners: a review

“…The performance of the amperometric enzyme electrode (Compagnone et al 1997), in terms of sensitivity, was superior to that of a previously reported aspartame biosensor and its detection limit was also lower than those achieved by spectrophotometric procedures, though a spectrophotometric procedure also provides a low detection limit (Fatibello-Filho et al 1999). The precision was similar in all the methods proposed, and always lower than 3.5% (relative standard deviation ).…”

“…The FIA biosensor was stable for at least 30 h of continuous use at room temperature (Male et al 1993). An aspartame electrode developed by covalent immobilization of alcohol oxidase and a-chymotrypsin (bovine pancreas) on the surf ace of a platinum-based hydrogen peroxide electrode was described by Compagnone et al (1997). The biosensor has been used for the measurement of aspartame with batch, ow-through and FI methods.…”

“…Di erent procedures for the elimination of these interferences have been tested (Compagnone et al 1997). In the spectrophotometric procedure based on ninhydrin, high citric acid and cyclamate concentrations caused a positive interference, but for more dilute solutions of these compounds interferences did not occur (Arau  jo .…”

Determinação espectrofotométrica de aspartame em adoçantes por injeção em fluxo usando um reator em fase sólida contendo fosfato de zinco imobilizado

“…Biossensores envolvendo diferentes enzimas e técnicas de imobilização estão descritos na literatura [15][16][17][18][19][20][21] . Um biossensor contendo a L-aspartase 19 e outro contendo essa enzima co-imobilizada com a carboxipeptidase A 20 imobilizadas sobre uma membrana de um eletrodo sensível a amônia foram utilizados na determinação de aspartame em diversos produtos dietéticos.…”