Molinate quantification in environmental water by a glutathione-S-transferase based biosensor

Area of Science:

• Environmental Science
• Analytical Chemistry
• Biotechnology

Background:

• Thiocarbamate herbicides like molinate pose risks to aquatic ecosystems.
• Accurate and rapid detection methods for environmental pollutants are crucial.

Purpose of the Study:

• To develop and validate a glutathione-S-transferase (GST) based biosensor for quantifying molinate in environmental water.
• To assess the biosensor's stability, reusability, and applicability in real-world samples.

Main Methods:

• Immobilization of GST onto a glassy carbon electrode using aminosilane-glutaraldehyde covalent attachment.
• Detection of molinate based on GST inhibition using differential pulse voltammetry.
• Validation of the biosensor against high-performance liquid chromatography (HPLC).

Main Results:

• The developed biosensor demonstrated a linear range of 0.19 to 7.9 mg L(-1) for molinate.
• A low detection limit of 0.064 mg L(-1) was achieved.
• The biosensor showed stability and reusability for 15 days and accurately quantified molinate in rice paddy floodwater.

Conclusions:

• The GST-based biosensor is a stable, reusable, and effective tool for quantifying molinate in environmental water.
• The developed method requires no sample preparation, enabling in situ and real-time analysis.
• This biosensor is suitable for screening environmental water samples, offering results comparable to HPLC.