Using Portable Glucose Meters for Precise Pathogen Detection in Food
News 30 9 月, 2024
Staphylococcus aureus is one of the most common foodborne pathogenic bacteria, known to cause various diseases. Recently, researchers have developed a sensitive and highly selective biosensor based on a personal glucose meter (PGM) platform to detect Staphylococcus aureus in food.
Why Use a Personal Glucose Meter (PGM) for Bacteria Detection?
PGMs are widely recognized for their portability, low cost, ease of use, broad applicability, and reliable quantitative results. Traditionally used for monitoring glucose levels in blood, PGMs have now been adapted for detecting ions, small molecules, nucleic acids, proteins, and more. This makes them an ideal portable detection platform for various applications, including food safety testing.
The hybridization chain reaction (HCR) is a chain-displacement reaction mediated by an initiator or target molecule. Due to its simplicity and high amplification efficiency, HCR has been widely used as an enzyme-free signal amplification method in nucleic acid detection. Combining the PGM platform with the HCR strategy, scientists have created a highly sensitive biosensor for detecting Staphylococcus aureus in food samples.
How the Biosensor Works
Figure 1 illustrates the detection mechanism. The capture probe P is attached to magnetic beads (MBs) and hybridized with the Staphylococcus aureus aptamer. When Staphylococcus aureus is present, the aptamer undergoes coupling, releasing the aptamer from the MBs and exposing the capture probe P. This probe acts as a trigger for the HCR process.
After HCR, long linear DNA chains containing alternating biotin-H1 and biotin-H2 sequences form on the MBs’ surface. Streptavidin-labeled invertase is then introduced, which binds to the MBs through biotin-streptavidin interactions. This invertase catalyzes the conversion of sucrose into glucose, generating a measurable signal that the PGM can quantify. By monitoring the PGM signal, the concentration of Staphylococcus aureus can be accurately determined. In the absence of Staphylococcus aureus, the capture probe P remains hybridized with the aptamer, keeping the biotin-H1 and biotin-H2 in a hairpin structure that prevents HCR.
Figure 1: Schematic of the Portable Detection Method for Staphylococcus aureus Using PGM and HCR
Benefits of the PGM-Based Staphylococcus aureus Biosensor
By utilizing the PGM platform and HCR strategy, researchers have developed a novel biosensor for Staphylococcus aureus detection. The cascading signal amplification by HCR allows the sensor to detect the bacterium with high sensitivity, achieving a limit of detection (LOD) as low as 2 CFU/mL. Additionally, the biosensor exhibits strong anti-interference capabilities and has been successfully applied to real food samples.
This method significantly enhances the sensitivity of sensors prepared using the HCR strategy and provides a new approach for developing accurate, sensitive, and portable tools for pathogen detection.
Conclusions
The PGM-based biosensor successfully detects Staphylococcus aureus in real food samples, offering results consistent with traditional plate counting methods. Unlike traditional methods, the PGM sensor significantly reduces the time required for detection, providing an ideal solution for the rapid, portable detection of bacterial pathogens. This approach holds great potential for quality control in agriculture, food production, import/export inspection, and food safety testing.