Sensitive detection of Campylobacter jejuni using nanoparticles enhanced QCM sensor

Area of Science:

• Biosensing
• Food Safety
• Analytical Chemistry

Background:

• Campylobacter jejuni is a major foodborne pathogen.
• Rapid and sensitive detection methods are crucial for food safety.
• Quartz Crystal Microbalance (QCM) offers a label-free detection platform.

Purpose of the Study:

• To develop a highly sensitive QCM-based immunosensor for Campylobacter jejuni detection.
• To optimize assay formats for enhanced sensitivity and specificity.
• To evaluate the sensor's performance against other foodborne pathogens.

Main Methods:

• Development of direct, sandwich, and gold-nanoparticles (AuNPs) amplified sandwich assays.
• Utilizing rabbit polyclonal and mouse monoclonal antibodies against C. jejuni.
• Performance evaluation using QCM, including limit of detection (LOD) and cross-reactivity studies.

Main Results:

• The AuNPs amplified sandwich assay with rabbit polyclonal capture antibodies showed the highest sensitivity.
• Achieved an LOD of 150 CFU/mL for C. jejuni.
• Demonstrated excellent specificity with low cross-reactivity (<7%) against Salmonella Typhimurium, Listeria monocytogenes, and Escherichia coli.

Conclusions:

• The developed QCM immunosensor provides a rapid and sensitive method for C. jejuni detection.
• This biosensor has the potential to reduce pre-enrichment steps and assay time in food safety testing.
• The technology shows promise for practical application in food pathogen surveillance.