Oxidase-loaded hydrogels for versatile potentiometric metabolite sensing

Area of Science:

• Electrochemistry
• Biosensor Technology
• Biomedical Engineering

Background:

• Continuous monitoring of biological metabolites requires robust, versatile, and reliable sensors.
• Electrochemical biosensors, using amperometric and voltammetric methods, are common but limited by electrode size-dependent signals susceptible to fouling.
• A need exists for electrochemical sensing techniques less dependent on electrode size for metabolite monitoring.

Purpose of the Study:

• To present open circuit potential as a reliable electrochemical technique for metabolite monitoring.
• To demonstrate the efficacy, longevity, sensitivity, and ease of fabrication of these novel sensors.
• To showcase the adaptability of this platform for detecting various analytes.

Main Methods:

• Developed an electrochemical sensor by immobilizing an oxidase enzyme in a chitosan hydrogel.
• Utilized the generation of hydrogen peroxide and consumption of oxygen upon substrate interaction to induce a potential change.
• Employed open circuit potential measurements, which are less sensitive to electrode size variations.

Main Results:

• Demonstrated glucose sensors with high efficacy, long lifetime, sensitivity, and ease of fabrication.
• Successfully miniaturized the sensors from macro- to microelectrode dimensions.
• Showcased the platform's versatility by fabricating a galactose sensor, indicating broad applicability.

Conclusions:

• Open circuit potential offers a robust and reliable alternative to traditional amperometric and voltammetric methods for metabolite sensing.
• The developed potentiometric sensor platform is versatile, sensitive, and easily fabricated.
• This work lays the groundwork for generalized potentiometric sensor applications across various metabolites and fields.