U-Shaped Plasmonic Fiber Probe for OTA Detection
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Solution Overview
Problem
Current methods for detecting ochratoxin-A (OTA) are expensive, time-consuming, and provide only semi-quantitative results, with a lack of portable, label-free sensors for on-site detection, particularly due to insufficient binding of small molecules leading to low sensitivity and limit of detection in plasmonic optical fiber sensors.
Innovation Solution
A U-shaped plasmonic optic fiber probe biosensor with a sensing layer of antibodies encapsulated in a metal organic framework (MOF) deposited on gold nanoparticles, utilizing localized surface plasmon resonance (LSPR) to detect changes in refractive index caused by OTA binding, allowing for label-free detection of OTA in ultra-low trace quantities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional ELISA methods are used for OTA detection, then semi-quantitative results can be obtained, but the process becomes expensive, time-consuming, and not suitable for on-site testing
Solution Approach 1:
The patent replaces conventional mechanical/chemical ELISA methods with an optical detection system based on LSPR. The fiber optic probe with gold nanoparticles detects OTA binding through optical signal changes, eliminating the need for multiple intricate steps of conventional ELISA while providing quantitative results in real-time
Solution Approach 2:
The invention changes the detection parameter from colorimetric/fluorometric signals requiring multiple steps to direct LSPR signal measurement. By monitoring the LSPR peak wavelength shift upon OTA binding, the system achieves rapid quantitative detection without the time-consuming steps of conventional ELISA
2Ease of operation
If label-free plasmonic optical fiber sensors are used for small molecule detection, then portability and simplicity are improved, but sensitivity and limit of detection deteriorate due to insufficient binding of small molecules
Solution Approach 1:
The patent creates a composite sensing layer combining gold nanoparticles with metal-organic frameworks (MOFs). The MOF component provides high surface area and numerous binding sites for OTA, while the gold nanoparticles provide LSPR signal. This composite structure amplifies the binding signal for small molecules, enabling sensitive detection in a portable format
Solution Approach 2:
The metal-organic framework provides a porous structure with high surface area that enhances the binding capacity for small OTA molecules. The porous network allows multiple binding sites per unit volume, amplifying the refractive index change signal and improving sensitivity for trace detection
3Device complexity
If direct label-free immunosensors are used for OTA detection, then device complexity is reduced, but stability and sensitivity are insufficient
Solution Approach 1:
The patent employs a composite structure of gold nanoparticles embedded in metal-organic framework. This composite provides both structural stability and enhanced sensitivity, as the MOF matrix stabilizes the gold nanoparticles and provides additional binding sites, improving reliability without significantly increasing device complexity
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
The system achieves highly sensitive and specific detection of OTA with a limit of detection as low as 1 fg/ml, overcoming limitations of stability and sensitivity in existing direct label-free immunosensors, enabling accurate quantification of OTA in food samples.
Implementation Method 1
The antibodies are encapsulated in a metal organic framework (203) deposited on gold nanoparticles, the sensing layer configured to detect a change in localized surface plasmon resonance (LSPR) property caused by binding of the analyte to the encapsulated antibodies
Implementation Method 2
MOF-based biocomposites are suitable for sensing applications, as these molecules are capable of accommodating within their structure, both the analyte to be detected and the biorecognition unit (enzymes, antibodies, etc.) by infiltration within the porous network
Implementation Method 3
an optical detector (103) connected to another leg of the U-bent probe through a second optical fiber connector (104b), wherein the optical detector (103) is configured to detect a change in optical intensity upon the interaction of the analyte with the sensing layer (205) of the biosensor (200), the change in intensity being proportional to the concentration of the analyte
Data Source
AI summary
The invention discloses a LSPR based label free immunosensing technique using a fiber optic system (100) for detecting an analyte molecule in a sample. The invention further discloses a U-shaped plasmonic optic fiber probe biosensor (200) to detect ochratoxin-A (OTA) in a sample and a method (300) of fabrication thereof. The optic fiber probe (101) biosensor (200) includes a sensing layer (205), a light source (102) to send light through the probe (101) and an optical detector (103) to detect a change in optical intensity due to a change in the localized surface plasmon resonance (LSPR) caused by binding of the analyte molecule to the antibody encapsulated in a metal organic framework. The antibody (204) in the sensing layer (205) is specific to the analyte molecule and configured to form an immunocomplex therewith.