Reagent-free electrochemical sensors for continuous bacteria monitoring

Overview

This technology offers a cost-effective, reagent-free approach to continuously monitoring bacteria in environments such as hospitals and bioreactors. It addresses a critical need for rapid, sensitive detection of specific bacterial strains without the need for reagents or complex sample preparation. Potential applications include hospital infection control, pharmaceutical manufacturing quality assurance, environmental monitoring, and bioprocess optimization.

The sensors are built on a novel electrochemical assay that uses nanoscale molecular pendulums to detect the presence of bacteria. When the pendulums bind to target bacteria, their movement kinetics on the electrode surface change dramatically, producing a strong, easily measured electrical signal. This approach enables highly sensitive detection in less than two minutes, making it suitable for real-time monitoring applications.

Technical specifications

Key features:

• Molecular pendulum design: Nanoscale probes attached to an electrode surface move freely; binding to target bacteria dramatically slows their kinetics, producing a large, measurable signal
• Reagent-free operation: No enzymes, labels, or additional reagents needed, simplifying workflow and reducing cost per test
• Rapid results: Detection in less than two minutes, suitable for point-of-care and continuous monitoring
• High sensitivity: Demonstrated detection of bacterial biomarkers at very low concentrations, with excellent signal-to-noise ratios due to the large size of bacterial targets
• Low-cost instrumentation: Operates with a potentiostat that can be miniaturized into a handheld device similar to a glucometer
• Flexible recognition: Uses antibodies or aptamers as recognition agents, enabling adaptation to different bacterial targets
• Multiplexing capability: A 1 cm × 1 cm chip is being developed to detect a panel of bacterial targets simultaneously
• Storage stability: Validated for six months under 75% humidity, supporting long-term storage and deployment
• Low unit cost: Sensor chips designed to cost less than $2 at low production volumes

Target bacteria validated or under development:

• Staphylococcus aureus
• Pseudomonas aeruginosa
• Ralstonia pickettii
• Brevundimonas diminuta
• Mycobacterium abscessus

Technology readiness level

The molecular pendulum technology was first developed in 2019 and has been validated for protein biomarker detection and direct detection of SARS-CoV-2 viral particles in patient saliva samples. Live bacteria detection has been demonstrated for S. aureus and P. aeruginosa, including real-time tracking of specific bacterial strains. Current efforts focus on developing a multiplexed 1 cm × 1 cm chip capable of detecting a panel of bacterial targets, validating specificity against a broad panel of non-target bacteria, and optimizing compatibility with diverse sample types. The integrated device, combining the sensor chip with a miniaturized 2 cm × 2 cm potentiostat, is designed to deliver results in under two minutes with no user intervention, positioning the technology for translation into practical monitoring systems.