A rapid binding test has been developed for the detection of bacteria using polymer-modified magnetic nanoparticles. Polydopamine (PDA) can effectively act as a sorbent even in water solution, and a PDA coating on magnetic nanoparticles (MNPs) was therefore prepared to bind Escherichia coli (E. coli). Albeit non-selective, PDA-modified magnetic nanoparticles (MNPs@PDA) show nearly 100% efficiency in binding E. coli. If E. coli, grown in tryptic soy broth medium, is analyzed by capillary electrophoresis (CE) using phosphate buffer as the background electrolyte, two peaks are found, while a single peak is found with carbonate buffer containing 0. 05% of poly(ethylene glycol). Self-polymerization of dopamine on E. coli at pH 9. 5 is also feasible. The detection of E. coli is demonstrated by adding quantum dots (QDs) to form a QDs-PDA-E. coli aggregate for better CE analysis.

Additional Metadata
Keywords Capillary electrophoresis, Escherichia coli, Polydopamine-coated magnetic nanoparticles, Quantum dots, Rapid binding test
Persistent URL dx.doi.org/10.1007/s00604-011-0712-2
Journal Microchimica Acta
Iqbal, Z. (Zafar), Lai, E. P, & Avis, T. (2012). Development of polymer-modified magnetic nanoparticles and quantum dots for Escherichia coli binding test. Microchimica Acta, 176(1-2), 193–200. doi:10.1007/s00604-011-0712-2