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High-sensitivity U-shaped biosensor for rabbit IgG detection based on PDA/AuNPs/PDA sandwich structure.
Pengxiang Chang1, Yirui Zhang1, Ailing Zhang1
1Tianjin Key Laboratory of Thin Film Electronics and Communication Devices, Engineering Research Center of Optoelectronic Devices and Communication Technology, Ministry of Education, College of Integrated Circuit Science and Engineering, Tianjin University of Technology, Tianjin 300384, China.
A novel U-shaped optical fiber biosensor coated with polydopamine (PDA) and gold nanoparticles (AuNPs) enhances detection sensitivity. This surface plasmon resonance (SPR) biosensor effectively detects low concentrations of rabbit immunoglobulin G (IgG).
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Optical Sensors
Background:
- Surface Plasmon Resonance (SPR) biosensors offer high sensitivity for biomolecular detection.
- U-shaped optical fibers enhance evanescent field penetration, improving SPR signal.
- Polydopamine (PDA) and gold nanoparticles (AuNPs) can enhance sensor surface properties and plasmonic effects.
Purpose of the Study:
- To develop a PDA/AuNPs/PDA sandwich structure modified U-shaped optical fiber SPR biosensor.
- To detect rabbit immunoglobulin G (IgG) with enhanced sensitivity and a lower limit of detection.
- To investigate the performance improvements offered by the combined U-shaped fiber and PDA/AuNPs/PDA structure.
Main Methods:
- Fabrication of a U-shaped optical fiber surface plasmon resonance (SPR) biosensor.
- Modification of the U-shaped fiber with a polydopamine (PDA)/gold nanoparticles (AuNPs)/PDA sandwich structure.
- Characterization of the sensor's refractive index (RI) sensitivity and its performance in detecting rabbit IgG.
Main Results:
- The U-shaped structure significantly increased evanescent field penetration depth.
- The PDA/AuNPs/PDA structure boosted SPR and localized SPR (LSPR) coupling efficiency, increasing surface area and activity.
- The sensor demonstrated a high RI sensitivity of 6,206.32 nm/RIU and a biosensor sensitivity of 0.153 nm/(ng/mL) for rabbit IgG detection, with a limit of detection (LOD) of 0.131 ng/mL.
Conclusions:
- The proposed PDA/AuNPs/PDA sandwich structure on a U-shaped optical fiber SPR biosensor significantly enhances detection performance.
- The sensor exhibits superior refractive index sensitivity and achieves a high biosensitivity and low LOD for rabbit IgG.
- This advanced biosensor provides a promising solution for detecting low-concentration biological analytes, with potential applications in medical diagnostics.
