Electronic pathogen detection sensors using aptamer-functionalized gap junctions for aqueous environments

Overview

This technology offers a novel approach to pathogen detection in aqueous environments using electronic sensors based on aptamer-functionalized gap junctions. The sensors are designed to be fast (1-100 seconds), thermally resettable for continuous use, and capable of detecting a range of pathogens including viruses (COVID-19, Zika, hepatitis A), bacteria (E. coli), and fungi. By leveraging the unique binding properties of aptamers and the electrical sensitivity of tunnel gap junctions, these sensors can identify pathogens based on their physical attributes such as size, shape, permittivity, and conductivity. The technology eliminates the need for reagents or trained operators, making it suitable for continuous, automated monitoring applications in water quality, clinical diagnostics, and food safety.

Technical specifications

Key features:

• Gap junctions sized between 70-120 nm, matched to pathogen dimensions for selective capture
• Aptamer coatings that bind specifically to surface proteins of target pathogens
• Impedance measurement at 10 kHz to detect pathogen presence
• Integrated fluidic chamber with temperature control for stable operation and thermal reset
• Electrophoretic attraction using positive voltage to reduce false negative rates
• Capacitance changes from 5 pF to 10-15 pF depending on viral load
• Limit of detection of approximately 10 viruses in 10 microliters of saliva
• False positivity and negativity rates in the 5-8 percent range
• Potential to differentiate between Gram-positive and Gram-negative bacteria using impedance signatures

Detection capabilities demonstrated:

• COVID-19 spike protein detection in saliva
• Zika virus detection
• E. coli binding and immobilization

Future development targets:

• Hepatitis A virus (27-32 nm linear)
• Acremonium fungi (2-3 by 4-8 micrometers)
• Integration with nano/micro-pore filtration for multi-pathogen detection

Technology readiness level

The technology has been validated with proof-of-concept demonstrations for COVID-19 and Zika virus detection, as well as E. coli binding. Current validation has focused on saliva-based COVID-19 detection, with demonstrated capacitance changes correlating to viral load and strategies developed to mitigate false positives from nanoparticles and exosomes. Future work aims to extend the platform to additional pathogens including hepatitis A and fungi, and to integrate sensors with nano/micro-pore filtration systems for broader environmental monitoring applications. The sensors are fabricated using standard microfabrication techniques, supporting scalability for commercial production.