Highly sensitive amperometric biosensor based on electrochemically-reduced graphene oxide-chitosan/hemoglobin...

Area of Science:

• Electrochemistry
• Biosensors
• Environmental Science

Background:

• Nitromethane (CH3NO2) is a crucial industrial chemical and a significant environmental pollutant.
• Sensitive and straightforward detection methods for CH3NO2 are essential for monitoring and control.

Purpose of the Study:

• To develop a novel amperometric biosensor for the sensitive detection of nitromethane (CH3NO2).
• To immobilize electrochemically-reduced graphene oxide (rGO), chitosan (CS), and hemoglobin (Hb) on a glassy carbon electrode (GCE) for enhanced performance.

Main Methods:

• Construction of a composite film (Hb-CS/rGO-CS) on a GCE.
• Characterization using scanning electron microscopy (SEM), infrared spectroscopy (IR), and electrochemical techniques.
• Optimization of biosensor parameters including scan rate and pH.

Main Results:

• The developed biosensor demonstrated direct electrochemistry with an accelerated electron-transfer rate (6.48 s⁻¹).
• Excellent catalytic activity towards CH3NO2 was observed.
• Achieved a wide linear detection range (5 μM–1.46 mM) and a low detection limit (1.5 μM).
• Exhibited fast amperometric response (<5s), high selectivity, reproducibility, and stability.

Conclusions:

• The Hb-CS/rGO-CS based biosensor provides a sensitive and reliable platform for CH3NO2 detection.
• The biosensor's performance characteristics make it suitable for monitoring nitromethane in complex real-world samples.
• This advancement offers a promising tool for environmental monitoring and industrial applications involving nitromethane.