Rapid disposable lipase activity sensor for automatic industrial application

Abstract

A low-cost disposable lipase activity sensor was developed and characterized overcoming the main drawbacks of the already existing disposable ones: insufficient reproducibility to be applied for automatic lipase activity quantification and complicated and long manual analytical procedure performed by qualified personnel. The sensor is based on a capacitor formation on an electrode surface by a substrate layer deposition possessing high electrical resistivity and dielectric constant (composite of olive oil mixed with BaTiO3 nanoparticles) serving as both: sensor sensitive layer and capacitor dielectric. Its decomposition by lipase catalyzed hydrolysis causes its thickness decrease resulting in capacitance increase proportional to the lipase activity. The sensor was characterized in terms of limit of quantification, linear quantification range, sensitivity, response time, precision, repeatability, storage time and the results are presented and discussed. The validation experiment showed excellent agreement with the standardized titrimetric method.

Keywords

• capacitive sensor
• automatic lipase activity quantification
• high permittivity lipase substrate