Electrochemical micro-device for rapid bacteria detection and identification in water

Overview

This solution offers a portable electrochemical micro-device designed for the rapid detection and identification of bacteria in water. The technology targets the 16S rDNA fragment, which contains both variable and constant regions. By designing aptamer probes that bind to species-specific variable regions, the device can not only quantify bacterial content but also distinguish between different bacterial types. The compact electrode chip is easy to carry and operate, making it suitable for field-based water quality monitoring. Because the platform is built around a changeable probe sequence, it can be rapidly reconfigured to target specific pathogens without redesigning the entire system.

Technical specifications

Key features:

• Aptamer-based electrochemical detection: Probes complementary to 16S rDNA variable regions are immobilized on the electrode surface to capture bacterial DNA fragments with species-level specificity.
• Signal amplification: A sandwich structure is formed on the electrode surface during detection, combined with ferrocene-gold nanostar composites to amplify the electrochemical signal for improved sensitivity.
• Integrated three-electrode system: Low-cost, compact design suitable for portable deployment.
• Reconfigurable targeting: Bacterial type specificity is achieved by simply changing the probe sequence, enabling flexible adaptation to different pathogens.
• Validated detection range: The sensor has demonstrated detection of specific mycoplasma DNA in the range of 0.1 ng/µL to 20 ng/µL.
• Workflow: Sample preparation includes screening with a mycoplasma detection kit, PCR amplification, and DNA sequence confirmation prior to electrochemical analysis.

Technology readiness level

The technology is currently at an early-to-mid stage of development. Preliminary validation has been completed for mycoplasma detection, demonstrating proof-of-concept performance with a detection range of 0.1–20 ng/µL. Planned next steps include designing complementary probe sequences for the 16S rDNA target, verifying probe-DNA binding affinity through gel electrophoresis, optimizing detection conditions (time, voltage range, signal probe performance, and detection mode), establishing a calibration curve correlating electrochemical signal with bacterial concentration, and conducting real-sample analysis across different water matrices. The device has not yet been validated in real water samples or against a broad panel of bacterial species beyond mycoplasma.