Lactose nano-probe optimized using response surface methodology.

Area of Science:

• Biotechnology
• Nanotechnology
• Enzyme Engineering

Background:

• Lactose intolerance affects a significant portion of the global population.
• Accurate detection of lactose in food products is crucial for consumer health and quality control.
• Existing methods for lactose detection may lack sensitivity or convenience.

Purpose of the Study:

• To develop a sensitive and stable lactose nano-probe for detecting lactose.
• To optimize the immobilization of beta-galactosidase (PsBGAL) onto gold nanoparticles (AuNps).
• To characterize the properties and performance of the developed nano-probe.

Main Methods:

• Immobilization of PsBGAL enzyme onto gold nanoparticles (AuNps) using a cysteamine-glutaraldehyde spacer arm.
• Optimization of immobilization efficiency using response surface methodology (Box-Behnken design).
• Characterization of the AuNp-PsBGAL conjugate using electron microscopy and spectroscopy.

Main Results:

• Achieved an enzyme immobilization efficiency of 140.81% onto AuNps.
• The immobilized enzyme exhibited enhanced catalytic efficiency and broader temperature/pH optima compared to soluble PsBGAL.
• The nano-probe demonstrated superior stability under dried conditions over six months and retained activity over five reuses.

Conclusions:

• The developed gold nanoparticle-based lactose nano-probe (AuNp-PsBGAL) offers a promising tool for lactose detection.
• The probe is suitable for quality control of lactose-hydrolyzed milk and estimating hidden lactose in various food products.
• This nanotechnology-based approach provides a stable, reusable, and efficient method for lactose analysis, benefiting lactose-intolerant consumers.