Rapid microbial detection biosensor using gold nanoparticle chemiluminescence assay

Overview

This biosensor technology enables rapid and accurate detection of microorganisms by leveraging disulfide-bond-containing proteins found on the outer structures of most microbial cells. Through chemical reduction of these proteins, microbial cells are coated with gold nanoparticles and detected using a gold nanoparticle-luminol chemiluminescence assay. The system delivers results in approximately 10 minutes with a limit of detection below 100 colony-forming units per milliliter, making it suitable for clinical diagnostics, food safety testing, water quality monitoring, pharmaceutical manufacturing, and environmental surveillance.

The technology addresses critical needs across multiple industries where rapid microbial detection is essential. Its combination of speed, sensitivity, cost-effectiveness, and simplicity makes it practical for both laboratory and field deployment, including continuous monitoring applications.

Technical specifications

Core detection mechanism:

• Targets disulfide-bond-containing proteins present on outer structures of nearly all microorganisms, with the exception of obligate anaerobes and intracellular parasites
• Uses a reducing agent to activate disulfide-bond proteins on microbial cell surfaces
• Activated cells are coated and concentrated with gold nanoparticles
• Detection occurs through a gold nanoparticle-luminol chemiluminescence assay where microorganisms interfere with chemiluminescence signal generation by inactivating the redox agent

Performance characteristics:

• Detection time of approximately 10 minutes
• Limit of detection below 100 cfu/mL
• Requires only small sample volumes
• Over 99 percent microbial capture efficiency demonstrated on gold surfaces
• Validated preliminary data confirms proof of concept

System advantages:

• High sensitivity and stability from the gold nanoparticle-luminol chemiluminescence system
• Cost-effective compared to conventional detection methods
• Simple enough to be developed into a continuous monitoring system
• User-friendly prototype development planned for real-world deployment

Technology readiness level

The technology has demonstrated proof of concept through preliminary laboratory data and prior published work on chemical activation of microbial disulfide-bond proteins and gold nanoparticle chemiluminescence assays. The research team has established over 99 percent capture efficiency for microbial isolation on gold surfaces and has shown the analytical potential of gold nanoparticle chemiluminescence for detection and quantification.

Future validation activities include synthesis and characterization of gold nanoparticles of various sizes, testing across six microorganisms encompassing bacterial and fungal species, exploration of different reducing agents to improve detection limits, and development of a user-friendly prototype. Performance will be benchmarked against laboratory gold standard methods through in-house validation, field trials, and pilot studies.