Advanced Lab-on-Fiber Optrodes Assisted by Oriented Antibody Immobilization Strategy.
Sarassunta Ucci1, Sara Spaziani2,3, Giuseppe Quero2,3
1Institute of Biostructures and Bioimaging, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy.
Biosensors
|November 24, 2022
Summary
Oriented antibody immobilization on lab-on-fiber (LoF) biosensors significantly enhances biomarker detection. This improved strategy achieves ultra-low detection limits for cancer diagnostics, outperforming current methods.
Area of Science:
- Biomedical Engineering
- Biosensing Technology
- Nanotechnology
Background:
- Lab-on-fiber (LoF) optrodes offer real-time, label-free biomarker detection for point-of-care applications.
- Current LoF platforms face limitations in sensitivity, hindering their translation for ultra-low detection limits, crucial for cancer diagnostics.
- Effective antibody immobilization is key for sensitive immune-biosensing, requiring uniform coverage and correct bioreceptor orientation.
Purpose of the Study:
- To investigate improved antibody immobilization strategies using hinge carbohydrates for enhanced LoF biosensor performance.
- To optimize biofunctionalization protocols and transfer them to different LoF platforms for validation.
- To assess the potential of these enhanced LoF biosensors for detecting cancer biomarkers like Cripto-1 at ultra-low concentrations.
Main Methods:
- Optimized antibody immobilization protocols using hinge carbohydrates on a microfluidic surface plasmon resonance (mSPR) device.
- Transferred the optimized strategy to two LoF platforms: a commercial biolayer interferometry (BLI) device and a homemade optical fiber meta-tip (OFMT) biosensor.
- Evaluated the detection of Cripto-1, a cancer-related biomarker, using both random and oriented antibody immobilization approaches.
Main Results:
- Oriented antibody immobilization resulted in a 10-fold enhancement in Cripto-1 detection compared to random immobilization.
- The OFMT-based LoF platform achieved a Cripto-1 detection limit of 0.05 nM, a 250-fold improvement over the commercial BLI platform.
- Detection capabilities of the OFMT platform were comparable to a commercial bench-top mSPR system.
Conclusions:
- Oriented antibody immobilization is a viable strategy to significantly enhance the sensitivity of LoF biosensors.
- The developed LoF biosensor platforms, particularly the OFMT-based one, demonstrate high potential for sensitive detection of clinically relevant biomarkers in the sub-ng/mL range.
- This research paves the way for advanced point-of-care diagnostics with improved capabilities for early cancer detection and monitoring.
