The use of DNA-immobilized quartz crystal microbalance (QCM) for rapid detection of
Salmonella has been demonstrated. The terminal 5'-phosphate group of a DNA fragment containing
Salmonella-specific 464 bp DNA was modified with ethylendiamine. The DNA was denatured by heating and covalently immobilized via glutaraldehyde on a QCM treated with 3-aminopropyltriethoxysilane. The QCM immobilized with a single stranded DNA fragment containing the
Salmonella-specific DNA was connected to Sogo Pharmaceutical Fragrance sensor SF-105W. The frequency of the QCM decreased by the addition of complementary single strand DNA. The frequency also decreased after incubation with the PCR reaction mixture from
Salmonella-genomic DNA and du primer. However, the frequency did not decrease after incubation with phage DNA, plasmid DNA or PCR reaction mixtures from
E. coli and
B. cereus. The frequency change of the QCM after incubation with complementary DNA was closely correlated to the amount of DNA in the sample. The correlation coefficient was 0.995. Strand separation of the DNA-DNA hybrid at the surface of QCM was achieved by exposure to 10mM NaOH. This allowed the immobilized 464-mer DNA to be reused. Chicken meat inoculated with
Salmonella Typhimurium IFO 12529 at 108 CFU/25g was cultured in EEM broth for 6h and selectively enriched in DMPBN medium for 18h. DNA was prepared from the culture and PCR was performed with the du primer. Using this
Salmonella-specific DNA immobilized QCM, a decrease in frequency was detected with the PCR reaction mixture.
View full abstract