Nanozyme linked multi-array gas driven sensor for real-time quantitative detection of Group A streptococcus.

Area of Science:

• Biomedical Engineering
• Diagnostic Technologies
• Microbiology

Background:

• Group A Streptococcus (GAS) causes millions of mild infections and hundreds of thousands of severe, potentially fatal invasive infections annually.
• Rapid, accurate, and real-time detection of GAS is crucial for timely clinical intervention and public health management.
• Existing diagnostic methods may lack the speed, sensitivity, or point-of-care accessibility required for effective GAS detection.

Purpose of the Study:

• To develop a novel nanozyme-linked multi-array gas-driven sensor (NLMAGS) for rapid, point-of-care detection of Group A Streptococcus (GAS).
• To evaluate the performance, sensitivity, and accuracy of the NLMAGS compared to established diagnostic techniques like ELISA and lateral flow immunoassays.

Main Methods:

• Synthesized platinum- and palladium-rich nanozyme particles (Au@Pt@PdNPs) for labeling antibodies as detection probes.
• Developed a double-antibody sandwich immunoassay using magnetic beads as capture probes and Au@Pt@PdNPs-labeled antibodies as detection probes.
• Quantified GAS by measuring oxygen production, catalyzed by the immune complex, which drives ink drops forward in the gas-driven sensor.

Main Results:

• The NLMAGS achieved a limit of detection (LOD) of 62 CFU mL⁻¹, which is 5 times lower than ELISA (334 CFU mL⁻¹).
• Demonstrated excellent quantitative detection of GAS in spiked samples with high correlation to ELISA (r = 0.99, P < 0.001).
• Outperformed traditional lateral flow immunoassays, showing a significantly lower LOD (62 CFU mL⁻¹ vs. 10⁴ CFU mL⁻¹).

Conclusions:

• The NLMAGS provides a highly sensitive and rapid method for quantitative GAS detection at the point-of-care within 2 hours.
• The sensor integrates nanozyme, immunoassay, and 3D printing techniques for enhanced performance and diagnostic capabilities.
• The NLMAGS shows significant potential for detecting various pathogens beyond GAS, offering a versatile diagnostic platform.