Bi-enzyme functionalized electro-chemically reduced transparent graphene oxide platform for triglyceride detection

Area of Science:

• Electrochemistry
• Biosensors
• Materials Science

Background:

• Graphene derivatives are increasingly used in biosensors for rapid bio-analyte detection.
• Traditional triglyceride biosensors often rely on unstable redox mediators like NAD+/NADH, leading to bioelectrode fouling and reduced shelf-life.

Purpose of the Study:

• To develop a novel triglyceride (TG) biosensor using a unique transducer based on toluidine blue (TB) absorbed by electrochemically reduced graphene oxide (ERGO) on an indium tin-oxide (ITO) electrode.
• To overcome the limitations of unstable redox mediators in TG detection by creating a more stable and efficient bioelectrode.

Main Methods:

• Fabrication of a TB/ERGO/ITO electrode.
• Co-immobilization of lipase (LIP) and glycerol dehydrogenase (GDH) onto the TB/ERGO/ITO surface to create the LIP-GDH/TB/ERGO/ITO bioelectrode.
• Electrochemical characterization using cyclic voltammetry to assess performance.

Main Results:

• The TB/ERGO/ITO electrode exhibited excellent reversible electrochemical properties.
• The fabricated LIP-GDH/TB/ERGO/ITO bioelectrode successfully detected tributyrin (a model TG) in the range of 50-400 mg dL⁻¹.
• The biosensor demonstrated high sensitivity (29 pA mg⁻¹ dL), rapid response time (12 s), long-term stability, and a low apparent Michaelis-Menten constant (0.18 mM), indicating high enzyme affinity.
• Negligible interference was observed when estimating TG in human serum samples.

Conclusions:

• The developed bi-enzymatic bioelectrode offers an efficient and stable platform for triglyceride detection.
• This novel interface demonstrates the potential of graphene derivatives in advanced bioelectronic devices.
• The proposed biosensor provides a promising alternative to existing methods, enhancing the reliability and lifespan of biosensors.