Using oligonucleotide-functionalized Au nanoparticles to rapidly detect foodborne pathogens on a piezoelectric biosensor.
A circulating-flow piezoelectric biosensor, based on an Au nanoparticle amplification and verification method, was used for real-time detection of a foodborne pathogen, Escherichia coli O157:H7. A synthesized thiolated probe (Probe 1; 30-mer) specific to E. coli O157:H7 eaeA gene was immobilized onto the piezoelectric biosensor surface. Hybridization was induced by exposing the immobilized probe to the E. coli O157:H7 eaeA gene fragment (104-bp) amplified by PCR, resulting in a mass change and a consequent frequency shift of the piezoelectric biosensor. A second thiolated probe (Probe 2), complementary to the target sequence, was conjugated to the Au nanoparticles and used as a "mass enhancer" and "sequence verifier" to amplify the frequency change of the piezoelectric biosensor. The PCR products amplified from concentrations of 1.2 x 10(2) CFU/ml of E. coli O157:H7 were detectable by the piezoelectric biosensor. A linear correlation was found when the E. coli O157:H7 detected from 10(2) to 10(6) CFU/ml. The piezoelectric biosensor was able to detect targets from real food samples.
Chen
Sz-Hau
SH
Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30005, Taiwan.
Wu
Vivian C H
VC
Chuang
Yao-Chen
YC
Lin
Chih-Sheng
CS
D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004563:Electrochemistry; D019453:Escherichia coli O157 / Q000235:genetics / Q000302:isolation & purification*; D029968:Escherichia coli Proteins / Q000235:genetics; D005516:Food Microbiology; D006046:Gold / Q000032:analysis; D053768:Metal Nanoparticles / Q000032:analysis*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D018829:Adhesins, Bacterial; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D009841:Oligonucleotides; C073819:eaeA protein, E coli; D006046:Gold