Surface Plasmon Resonance AnalyzerThe Surface Plasmon Resonance Analyzer (SPR) is a physical instrument based on Surface Plasmon Resonance (SPR) technology, which is widely used for label free real-time detection of intermolecular interactions, especially in pesticide residue screening and pathogen detection, showing great potential.

1、 Principle of Surface Plasmon Resonance Technology

The SPR phenomenon occurs at the interface of metal thin films. When incident light is directed at a specific angle onto the metal thin film, it triggers collective oscillations of free electrons in the metal, known as surface plasmon oscillations. When the frequency of the incident light matches the oscillation frequency of the surface plasma, resonance occurs, resulting in a sharp decrease in the intensity of the reflected light. This resonance angle will change with the refractive index of the surface medium of the metal thin film, and the change in refractive index is closely related to the change in surface material mass caused by molecular binding or dissociation. Therefore, by monitoring changes in reflected light intensity, real-time detection of intermolecular interactions can be achieved.

2、 Application of pesticide residue screening

In terms of pesticide residue screening, SPR analyzer has the advantages of high sensitivity, fast response speed, and no need for labeling. By fixing specific receptor molecules on the surface of the SPR sensor chip, when pesticide residues in the test sample bind to the receptor molecules, it will cause a change in the refractive index of the chip surface, which will be captured by the SPR analyzer and converted into electrical signals for output. This technology can not only achieve rapid screening of pesticide residues, but also simultaneously detect multiple pesticide residues, greatly improving detection efficiency and accuracy.

For example, there is a multi-channel surface plasmon resonance pesticide residue detection device that combines wall breaking components, exhaust components, and driving devices to extract all substances inside and outside the skin of fruits and vegetables, and avoid distortion of test results by expelling bubbles. This device has a compact structure, stable operation, and high system integration, making it very suitable for on-site detection at the source such as in the field.

3、 Application of pathogenic bacteria detection

In terms of pathogen detection, SPR analyzers have also shown great potential for application. By coupling specific antibodies onto the surface of SPR sensor chips, direct detection of specific pathogenic bacteria can be achieved. When pathogenic bacteria in the test sample bind to antibodies on the surface of the chip, it also causes a change in the refractive index of the chip surface, which is then captured by the SPR analyzer. This technology can not only be used for rapid detection of pathogenic bacteria in aquatic products, but also extended to pathogenic bacteria detection in fields such as food and medicine.

For example, research has successfully established SPR biosensor technology for detecting pathogenic bacteria in aquatic products, including direct SPR method, double antibody sandwich method, and dual channel method. These methods have the advantages of high sensitivity, strong specificity, and good repeatability, and can be used for the detection of actual samples.

4Surface Plasmon Resonance AnalyzerAdvantages and Challenges

The application of SPR analyzer in pesticide residue screening and pathogen detection has the following advantages:

Real time label free detection: No need to label the sample, the interaction process between molecules can be monitored in real time.

High sensitivity: capable of detecting small changes in refractive index, thus enabling the detection of trace substances.

High throughput detection: High throughput sample detection can be achieved through multi-channel design or automatic sampler configuration.

However, SPR analyzers also face some challenges in their application process:

Selection and fixation of receptor molecules: It is necessary to select appropriate receptor molecules and fix them on the chip surface to ensure the specificity and accuracy of detection.

Sample pretreatment: For complex samples, appropriate pretreatment may be necessary to eliminate interfering factors.

Maintenance and calibration of instruments: Regular maintenance and calibration of instruments are required to ensure their stability and accuracy in performance.

Surface plasmon resonance analyzer has shown great potential and advantages in pesticide residue screening and pathogen detection. With the continuous development and improvement of technology, we believe it will play an important role in more fields.