Determination of sulphate-reducing bacteria based on vancomycin-functionalized magnetic nanoparticles using a modification-free quartz crystal microbalance.
A fast, sensitive and reliable quartz crystal microbalance (QCM) biosensor is described for the selective detection of the marine pathogenic sulphate-reducing bacterium (SRB), D. desulfotomaculum. Based on the amplification of the response of vancomycin-functionalized magnetic nanoparticles (Van-mNPs), under an external magnetic field, the bacteria-mNPs conjugates attach to the surface of an Au electrode. The QCM biosensor gave a distinct response to the vancomycin-sensitive, D. desulfotomaculum, but had no obvious response to the vancomycin-resistant bacterium, Vibrio anguillarum. The effects of the optimization conditions such as the incubation time and pH on the detection were also investigated, respectively. Optimised assays showed that the biosensor could obtain the best response with a 30 min incubation of the bacteria with the Van-mNPs. A linear relationship between the QCM response and the logarithm of the bacterial concentration was observed in the range of 1.8 x 10(4) to 1.8 x 10(7)cfu/ml. The sensor system has a potential for further applications and provides a facile and sample method for detection of pathogenic bacteria.
Wan
Yi
Y
Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China.
Zhang
Dun
D
Hou
Baorong
B
D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D001681:Biological Assay / Q000295:instrumentation*; D015374:Biosensing Techniques / Q000295:instrumentation*; D015169:Colony Count, Microbial / Q000295:instrumentation*; D045859:Desulfotomaculum / Q000187:drug effects / Q000378:metabolism*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D018189:Immunomagnetic Separation / Q000295:instrumentation*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013431:Sulfates / Q000737:chemistry / Q000378:metabolism; D014640:Vancomycin / Q000008:administration & dosage*
D000900:Anti-Bacterial Agents; D013431:Sulfates; D014640:Vancomycin