Detection of Vibrio cholerae Using the Intrinsic Catalytic Activity of a Magnetic Polymeric Nanoparticle

A novel and sensitive magnetic polymeric nanoparticle (MPNP)–polymerase chain reaction–colorimetry (magneto–PCR–colorimetry) technique was developed for detection of Vibrio cholerae (V. cholerae). The technique involved an amplification of V. cholerae DNA on the surface of an MPNP and then employed the intrinsic catalytic activity of the MPNP to detect the target gene by colorimetry. An amino-modified forward primer was covalently labeled onto the MPNP surface which would bind to PCR product during PCR cycling. By employing the catalytic activity of the MPNP, the analysis of PCR product bound MPNP yielded a sensitivity of 10³ CFU/mL of V. cholerae in buffer system within 4 h. The specificity and efficiency of the technique were investigated by using various bacterial DNAs in drinking and tap water.