Array lead zirconate titanate/glass piezoelectric microcantilevers for real-time detection of Bacillus anthracis with 10 spores/ml sensitivity and 1/1000 selectivity in bacterial mixtures.
An array of three identical piezoelectric microcantilever sensors (PEMSs) consisting of a lead zirconate titanate layer bonded to a glass layer was fabricated and examined for simultaneous, in situ, real-time, all-electrical detection of Bacillus anthracis (BA) spores in an aqueous suspension using the first longitudinal extension mode of resonance. With anti-BA antibody immobilized on the sensor surfaces all three PEMS exhibited identical BA detection resonance frequency shifts at all tested concentrations, 10-10(7) spores/ml with a standard deviation of less than 10%. The detection concentration limit of 10 spores/ml was about two orders of magnitude lower than would be permitted by flexural peaks. In blinded-sample testing, the array PEMS detected BA in three samples containing BA: (1) 3.3x10(3) spores/ml, (2) a mixture of 3.3x10(3) spores/ml and 3.3x10(5) S. aureus (SA) and P. aeruginosa (PA) per ml, and (3) a mixture of 3.3x10(3) spores/ml with 3.3x10(6) SA+PA/ml. There was no response to a sample containing only 3.3x10(6) SA+PA/ml. These results illustrate the sensitivity, specificity, reusability, and reliability of array PEMS for in situ, real-time detection of BA spores.
McGovern
John-Paul
JP
Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA.
Shih
Wei-Heng
WH
Rest
Richard F
RF
Purohit
Mitali
M
Mattiucci
Mark
M
Pourrezaei
Kambiz
K
Onaral
Banu
B
Shih
Wan Y
WY
D000388:Air; D001408:Bacillus anthracis; D001419:Bacteria; D015374:Biosensing Techniques / Q000295:instrumentation*; D004581:Electronics / Q000295:instrumentation; D004867:Equipment Design; D005188:False Negative Reactions; D005189:False Positive Reactions; D005898:Glass; D007854:Lead; D008855:Microscopy, Electron, Scanning; D011550:Pseudomonas aeruginosa; D012680:Sensitivity and Specificity; D013171:Spores, Bacterial; D013211:Staphylococcus aureus; D013997:Time Factors; D014025:Titanium; D014867:Water; D015040:Zirconium
D014867:Water; C065536:lead titanate zirconate; D007854:Lead; D015040:Zirconium; D014025:Titanium