Fluorescence Probe Aptamer Optical Sectioning for Aflatoxin B1 Detection
Solution Overview
Problem
Current methods for detecting aflatoxin B1 (AFB1) in food samples are limited by their inability to achieve precise and controlled detection due to the complexity of samples and the passive nature of target recognition units.
Innovation Solution
A fluorescence analysis method based on optical sectioning is developed, using a fluorescence probe combination consisting of a fluorescence probe aptamer and a PC-strand. This method involves real-time operation and remote triggering of light to selectively activate the target recognition unit, allowing for precise detection of AFB1.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a target probe is always active to detect AFB1, then the detection response is immediate, but the specificity and controllability are reduced due to passive detection in complex samples
Solution Approach 1:
The target probe is pre-prepared in an inactive state (blocked by the blocking strand), and the detection is triggered by light activation at the appropriate time. This preliminary preparation allows the system to switch from passive to active detection state, improving both specificity and controllability while maintaining rapid response when activated
Solution Approach 2:
The detection system transitions from a static passive probe to a dynamic controllable system. The probe's activity state is dynamically switched between inactive (blocked) and active (light-activated) states, allowing precise control over when detection occurs, thereby improving both specificity and response timing in complex food samples
2Measurement precision
If light is used to activate the target recognition unit, then the detection precision is improved through optical sectioning, but the detection process becomes more complex
Solution Approach 1:
A photocleavable blocking strand serves as an intermediary that mediates between the light signal and the target probe activation. The blocking strand contains a photocleavable group that specifically absorbs light at a certain wavelength, and upon light irradiation, it decomposes to release the target probe. This intermediary mechanism simplifies the overall system by using a straightforward photochemical reaction rather than complex optical sectioning apparatus
Solution Approach 2:
The patent replaces complex mechanical or optical sectioning systems with a photochemical mechanism. Instead of using physical optical sectioning apparatus to achieve spatial and temporal control, the system uses light-induced decomposition of the photocleavable blocking strand to activate detection, thereby reducing device complexity while maintaining precision
3Measurement precision
If a fluorescence probe combination with photocleavable group is used, then the detection sensitivity is enhanced through optical sectioning, but the manufacturing complexity increases
Solution Approach 1:
The detection system is segmented into distinct functional modules: the target probe with fluorescent label, the blocking strand with photocleavable group, and the quenching strand. This segmentation allows each component to be independently synthesized and optimized, simplifying the overall manufacturing process while enabling high detection sensitivity through the coordinated action of these separate elements
Solution Approach 2:
The fluorescence probe combination is pre-assembled with the photocleavable blocking strand in an inactive state during manufacturing. The target probe, blocking strand, and quenching strand are combined in specific ratios and stored as a ready-to-use reagent system. This preliminary assembly simplifies manufacturing by avoiding the need for complex on-site assembly procedures while maintaining high detection sensitivity when activated by light
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 method achieves high sensitivity and specificity in detecting AFB1, with the ability to distinguish AFB1 from structurally similar molecules like ochratoxin and zearalenone, and is applicable to food samples such as rice, corn, and soybeans.
Implementation Method 1
a photocleavable (PC) group is located between 10th base pair (bp) and 11th bp of the nucleotide sequence of SEQ ID NO: 2
Implementation Method 2
a carboxyfluorescein (FAM) group is located at a 3′ end of the nucleotide sequence of SEQ ID NO: 1
Data Source
AI summary
A method for detecting an AFB1 content using fluorescence analysis based on optical sectioning is provided, which relates to the field of biological detection technologies. The method includes steps for detecting the AFB1 content by using a fluorescence probe combination, which includes fluorescence probes aptamer and PC-strand. The nucleotide sequence of the aptamer is shown as SEQ ID NO: 1, and a FAM group is labeled at a 3′ end of the nucleotide sequence shown as SEQ ID NO: 1. The nucleotide sequence of the PC-strand is shown as SEQ ID NO: 2, a TAMRA group is labeled at a 5′ end of the nucleotide sequence shown as SEQ ID NO: 2, and a PC group is labeled between 10th bp and 11th bp of the nucleotide sequence shown as SEQ ID NO: 2. The method can achieve photosensitive detection of AFB1, with high detection sensitivity and strong specificity.