A microband lactate biosensor fabricated using a water-based screen-printed carbon ink

Area of Science:

• Electrochemistry
• Biosensor Technology
• Materials Science

Background:

• Screen-printed carbon electrodes (SPCEs) are versatile platforms for electrochemical sensing.
• Hydrogen peroxide (H2O2) and lactate are key analytes in biological and metabolic studies.
• Developing simple, cost-effective biosensors for these analytes is crucial for in-vitro monitoring.

Purpose of the Study:

• To demonstrate the fabrication of screen-printed carbon microband electrodes from water-based ink for H2O2 detection.
• To construct microband biosensors using the same ink formulation with lactate oxidase for lactate measurement.
• To characterize the electrochemical performance and assess the suitability for cell metabolism monitoring.

Main Methods:

• Fabrication of microband electrodes by cutting conventional SPCEs.
• Electrochemical characterization using cyclic voltammetry, chronoamperometry, and amperometry.
• Incorporation of lactate oxidase into the ink for biosensor development.
• Electrochemical detection of H2O2 and lactate under varying conditions.

Main Results:

• Screen-printed carbon microband electrodes successfully detected H2O2 with sigmoidal cyclic voltammograms and a current density of 4.2 mA cm(-2).
• Mass transport was identified as a mixture of radial and planar diffusion, with radial diffusion predominating under hydrodynamic conditions.
• Lactate microband biosensors showed linear detection up to 6mM lactate within a 1-10mM dynamic range, with a lower limit of detection of 289 microM.
• Lactate oxidase incorporation did not compromise the electrode's H2O2 detection capabilities.

Conclusions:

• Water-based ink facilitates the fabrication of screen-printed carbon microband electrodes for H2O2 detection.
• These electrodes can be readily adapted into microband biosensors for lactate measurement.
• The developed biosensor platform is suitable for electrochemical monitoring of lactate, offering potential for in-vitro cell metabolism studies.