A Simple Potentiometric Biosensor based on Carboxylesterase for the Analysis of Aspartame

A potentiometric aspartame biosensor was fabricated by simply depositing the carboxylesterase (CES)-bonded poly(n-butyl acrylate-n-acryloxysuccimide) [CES-poly(nBA-NAS)] microspheres on a Ag/AgCl screen-printed pH selective electrode. The transducer made from non-plasticized polyacrylate membrane containing hydrogen ionophore and lipophilic salt. immobilized CES enzyme catalyzed enzymatic hydrolysis of to L-aspartic acid (L-Asp), L-phenylalanine methanol. Potentiometric determination concentration performed quantifying ion produced L-Asp. exhibited good selectivity with near Nernstian response. sensitivity closed value, i.e., 50-52 mV decade-1 dynamic linear response range 10-5 10-2 M detection limit approaching 10-6 M. demonstrated repeatability reproducibility relative standard deviation (RSD) 1.9% 1.6%, respectively (n=3). be reliable for determining content in sweetener samples comparable conventional high-performance liquid chromatography (HPLC) method analysis.