Surface plasmon resonance biosensor for enrofloxacin based on deoxyribonucleic acid

Area of Science:

• Analytical Chemistry
• Biosensor Technology
• Molecular Biology

Background:

• Enrofloxacin is a widely used fluoroquinolone antibiotic.
• Accurate detection of enrofloxacin residues in food is crucial for public health.
• Existing detection methods can be complex and time-consuming.

Purpose of the Study:

• To develop a novel DNA-based surface plasmon resonance (SPR) biosensor for the detection of enrofloxacin.
• To evaluate the sensor's performance using real biological samples, specifically milk.
• To establish a simple and direct method for enrofloxacin determination.

Main Methods:

• Immobilization of denatured DNA onto a gold-coated glass surface using layer-by-layer co-deposition with a cationic polymer.
• Utilizing heating to denature DNA for immobilization.
• Employing surface plasmon resonance (SPR) for real-time detection of enrofloxacin binding.
• Testing the sensor with milk samples spiked with known enrofloxacin concentrations.

Main Results:

• The developed biosensor demonstrated effective immobilization of DNA.
• Direct and simple determination of enrofloxacin in milk samples was achieved.
• The sensor response followed a Langmuir binding isotherm, showing linearity up to approximately 20 microg/mL.
• The limit of detection for enrofloxacin in milk samples was determined to be 3 microg/mL.

Conclusions:

• A DNA-based SPR biosensor is a viable tool for enrofloxacin detection.
• The sensor provides a sensitive, simple, and direct method for enrofloxacin analysis in milk.
• This approach has potential for rapid screening of antibiotic residues in food products.