Unveiling Molecular Fingerprints of Bacteria on Nanoplasmonic Sensors

The recent pandemic has underscored the severe global threat posed by infectious diseases. Disease diagnosis and surveillance need accurate and efficient detection systems. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are the main causes of infections in humans. We present a nanoplasmonic detection platform designed to simultaneously identify E. coli and S. aureus in a single system. This method involves synthesizing molecular fingerprints, i.e., molecularly imprinted polymers (MIPs), of bacteria for each target bacterium and integrating gold nanoparticles (AuNPs) to create a nanoplasmonic system for precise bacterial identification. Then, AuNP-decorated bacteria-MIPs were strategically placed in 96-well plates. This arrangement permitted the simultaneous detection of numerous bacteria on the same platform, with a detection range of 1 × 10⁵ to 1 × 10⁹ cfu/mL and a limit of detection of 4.8 × 10⁴ cfu/mL for E. coli and 4.2 × 10⁴ cfu/mL for S. aureus. Bacteria-MIPs were tested against Gram-specific bacteria and shown to be selective. Artificial urine and serum spiked samples were used to test the platform effectiveness in simulated infection scenarios. The target microorganisms were detected in complicated matrices with great sensitivity. Consequently, bacteria-MIPs’ features make them an attractive choice for diagnostic system integration, allowing simultaneous detection of different bacteria on a plate and varied clinical and environmental applications.