Dispersible Conjugated Polymer Nanoparticles as Biointerface Materials for Label-Free Bacteria Detection

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Rapid and cost-effective bacterial detection is crucial for public health, food safety, and medical diagnostics.
• Impedimetric sensors offer a reliable and user-friendly approach for real-time bacterial monitoring.
• Existing methods often require complex sample preparation or lack sensitivity and specificity.

Purpose of the Study:

• To develop a novel biointerface material for label-free impedimetric detection of Escherichia coli (E. coli).
• To create a solution-processable nanoparticle system for enhanced electrochemical sensing capabilities.
• To evaluate the performance of the developed biosensor in real-world water samples.

Main Methods:

• Fabrication of amphiphilic poly(3-hexylthiophene)-b-poly(3-triethylene-glycol-thiophene) (P3HT-b-P3TEGT) core-shell nanoparticles.
• Decoration of nanoparticles with mannose for targeted E. coli recognition.
• Characterization of self-assembly and micelle formation using techniques like 2D-NMR and DLS.
• Evaluation of E. coli detection using electrochemical impedance spectroscopy (EIS) and microscopy.

Main Results:

• The mannose-functionalized P3HT-b-P3TEGT nanoparticles exhibited targeted binding to E. coli pili protein.
• The impedimetric biosensor demonstrated a detection range of 10^3 to 10^7 cfu/mL for E. coli.
• The sensor showed selectivity against Gram-positive bacteria and was successfully applied to detect bacteria in tap and Nile water samples.

Conclusions:

• Functionalized conjugated polymer nanoparticles are suitable for electrode materials in biosensors.
• The developed mannose-functionalized P3HT-b-P3TEGT nanoparticle system offers a promising platform for low-cost, label-free impedimetric bacterial detection.
• This approach has significant potential for applications in environmental monitoring and public health surveillance.