Interdigitated electrodes based on impedance biosensor for sensing peptide LL-37

Area of Science:

• Biomedical Engineering
• Immunology
• Analytical Chemistry

Background:

• The antimicrobial peptide LL-37 is a key component of the human innate immune system.
• Elevated LL-37 levels in urine are associated with urinary tract infections (UTIs).
• Accurate and sensitive detection of LL-37 can aid in UTI diagnosis.

Purpose of the Study:

• To design and validate a novel biosensor for the detection of LL-37 in human urine.
• To establish LL-37 as a potential biomarker for UTI diagnosis.
• To achieve high sensitivity and specificity in LL-37 detection.

Main Methods:

• Fabrication of a biosensor utilizing an interdigitated electrode on a printed-circuit board (PCB).
• Surface modification of the electrode with 3-mercaptopropionic acid.
• Immobilization of anti-LL37 antibodies to enhance biosensor specificity.
• Impedance measurement and calculation, accounting for jig impedance, to quantify LL-37 concentration.

Main Results:

• The developed biosensor demonstrated effective detection of LL-37.
• The biosensor achieved a sensitivity of 50 μg/mL for LL-37 in urine samples.
• The antibody immobilization strategy improved the specificity of the detection.

Conclusions:

• The developed biosensor shows promise as a diagnostic tool for UTIs.
• LL-37 can serve as a reliable indicator for UTI diagnosis.
• The impedance-based biosensor offers a sensitive and specific method for detecting LL-37 in biological fluids.