Highly Sensitive Detection of Bacteria by Binder-Coupled Multifunctional Polymeric Dyes

Area of Science:

• Polymer Chemistry
• Bioconjugation
• Biosensing
• Microbiology

Background:

• Traditional pathogen identification methods are often complex and time-consuming, posing a significant challenge in managing infectious diseases.
• There is a need for rapid, sensitive, and specific diagnostic tools for pathogen detection and bioimaging.

Purpose of the Study:

• To develop well-defined, multifunctional copolymers incorporating rhodamine B dye for advanced bioimaging and biosensing applications.
• To create a novel fluorescent polymeric dye-binder complex for enhanced pathogen detection and visualization.

Main Methods:

• Synthesis of multifunctional copolymers using atom transfer radical polymerization (ATRP) with a biotin-functionalized initiator and oxygen-tolerant photoredox/copper dual catalysis.
• Conjugation of biotinylated dye copolymers to antibodies (Ab) or cell-wall binding domains (CBD) to create specific binder complexes.
• Evaluation of the fluorescent polymeric dye-binder complexes for bioimaging of *Staphylococcus aureus* using flow cytometry and confocal microscopy.

Main Results:

• Efficient synthesis of copolymers with multiple fluorescent dyes was achieved via ATRP.
• The resulting biotinylated dye copolymers, when conjugated to Ab or CBD, formed highly fluorescent polymeric dye-binder complexes.
• These complexes demonstrated enhanced fluorescence and high target selectivity for *Staphylococcus aureus* bioimaging.

Conclusions:

• The developed ATRP-derived multifunctional polymeric dyes offer a promising platform for advanced biosensors.
• These polymeric dyes exhibit potential for sensitive detection of target DNA, proteins, and bacteria.
• The technology shows significant promise for improved bioimaging applications in microbiology and diagnostics.