SPR Sensor Biointerface with Iron Oxide Nanoparticles
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Solution Overview
Problem
Current surface plasmon resonance (SPR) sensors face challenges in detection sensitivity and stability, particularly for small molecules and low binding levels, due to the instability of colloidal gold particles and complex linkage processes, as well as limited immobilization yields for acidic ligands.
Innovation Solution
The implementation of self-assembled monolayers (SAMs) with rigid units adjacent to the metal surface, reversible entrapment methods for ligand loading, and the use of amorphous iron oxide nanoparticles for signal amplification, which enhance detection ease and sensitivity by increasing the refractive index change and allowing magnetic separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If colloidal gold particles are used for signal amplification, then detection sensitivity is improved, but particle stability deteriorates
Solution Approach 1:
The patent changes the material parameter from colloidal gold to amorphous iron oxide nanoparticles, which provide similar signal amplification through refractive index changes but offer superior stability and additional magnetic separation capabilities
Solution Approach 2:
The patent uses composite structures by coating amorphous iron oxide nanoparticles with stabilizing agents and functional ligands, creating a composite material that combines magnetic properties, stability, and analyte binding capability
2Quantity of substance
If complex linkage processes are used for ligand immobilization, then binding capacity is improved, but process complexity increases
Solution Approach 1:
The patent extracts the complex multi-step linkage processes and replaces them with a simplified direct immobilization method where ligands are directly attached to the amorphous iron oxide nanoparticle surface through surface chemistry, achieving high binding capacity without complex intermediate steps
Solution Approach 2:
The patent uses the amorphous iron oxide nanoparticle surface as an intermediary platform that provides inherent binding sites for ligands, eliminating the need for complex linker chains and intermediate immobilization steps required in traditional SPR sensor preparation
3Quantity of substance
If traditional immobilization methods are used, then ligand attachment is achieved, but immobilization yield deteriorates for acidic ligands
Solution Approach 1:
The patent changes the surface chemistry parameters of the immobilization platform by using amorphous iron oxide nanoparticles with tunable surface properties that can be optimized for acidic ligands, unlike traditional gold surfaces that have poor immobilization yield for acidic ligands
Solution Approach 2:
The patent copies the beneficial surface properties of materials known to interact well with acidic ligands and applies them to the nanoparticle surface, creating a platform that overcomes the limitations of traditional gold surface immobilization for acidic molecules
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly improves the sensitivity and stability of SPR sensors by creating a dense, stable biointerface for ligand binding and amplifying the SPR signal through amorphous iron oxide nanoparticles, enabling more accurate and efficient detection of analytes.
Implementation Method 1
A surface plasmon resonance (SPR) sensor measures changes of refractive index in a dielectric biointerface on a thin conductor using the dependence of the surface plasmon wave vector on the refractive index
Implementation Method 2
the analyte can be detected quantitatively in a fluid contacting the biointerface due to the change in refractive index by addition of the analyte to the biointerface
Implementation Method 3
allowing magnetic separation
Data Source
AI summary
Surface plasmon resonance (SPR) sensor biointerface with a rigid thiol linker layer and/or interaction layer ligand loading with reversible collapse and/or iron oxide nanoparticle sensor response amplification.