A simple and rapid detection system for oral bacteria in liquid phase for point-of-care diagnostics using magnetic nanoparticles

Loi Tonthat, Shunnosuke Takahashi, Hidehiko Onodera, Kazuhiko Okita, Shin Yabukami, Kotone Yokota, Maiko Furuya, Hiroyasu Kanetaka, Yoshinori Miura, Hideki Takahashi, Yoshihiko Watanabe, Ritsuko Akiyama
2019 AIP Advances  
This study describes a user-friendly and rapid detection system of oral bacteria in the liquid phase for point of care testing based on magnetic immunoassay. We focused on the dependence of the strength of external magnetic field required to switch the magnetic moments of nanoparticles bound to bacteria on the bacteria concentration. The results obtained indicate that the required field strength increases linearly as a function of log concentration of Porphyromonas gingivalis cultured in the
more » ... cultured in the range of 10 3 -10 9 CFU/mL. Similarly, the required field strengths for Streptococcus mutans and Pseudomonas aeruginosa increase monotonically when their concentrations increase, whereas the required field strength for Escherichia coli decreases monotonically when its concentration increases. We then measured the concentration of Porphyromonas gingivalis in the saliva collected from elderly people in a geriatric health services facility and the results using the developed system had a correlation with those using a commercial bacteria counter.
doi:10.1063/1.5130437 fatcat:ypcys4hmireupipulcpiotqtfu