Enzymatic Galvanic Redox Potentiometry for In Vivo Biosensing

Area of Science:

• Electrochemistry
• Biosensors
• Neuroscience

Background:

• Redox potentiometry is a promising in vivo sensing platform with good neuronal compatibility.
• Enzyme electrodes offer selectivity but face challenges in fast response times due to protein fouling.
• Galvanic redox potentiometry (GRP) sensors are reliable and biocompatible but lack the selectivity of enzyme electrodes.

Purpose of the Study:

• To develop a novel enzymatic galvanic redox potentiometry (GRP) biosensor with an improved response time.
• To combine the selectivity of enzyme electrodes with the reliability of GRP sensors for in vivo applications.
• To demonstrate the utility of this new biosensor for monitoring glucose dynamics in the brain.

Main Methods:

• Fabrication of an enzymatic GRP biosensor using flavin adenine dinucleotide-dependent glucose dehydrogenase and carbon black.
• Characterization of the biosensor's response to glucose, including linearity, selectivity, and reversibility.
• In vivo monitoring of glucose dynamics in rat brain using the developed GRP biosensor.

Main Results:

• The enzymatic GRP biosensor exhibited a rapid response to glucose with a linear relationship between open-circuit voltage (EOC) and the logarithm of glucose concentration (100 μM to 2.65 mM).
• The biosensor demonstrated high selectivity over oxygen and common neurochemicals, along with good reversibility and sensitivity.
• Successful in vivo monitoring of glucose dynamics in rat brain was achieved.

Conclusions:

• The developed enzymatic GRP biosensor represents a novel platform for in vivo potentiometric biosensing.
• This approach successfully integrates enzyme selectivity with GRP sensor reliability and fast response times.
• The study paves the way for advanced in vivo monitoring of chemical events with high reliability.