Abstract
Herein we reported the development of aptamer-based biosensors (aptasensors) based on label-free aptamers and gold nanoparticles (AuNPs) for detection of Escherichia coli (E. coli) O157:H7 and Salmonella typhimurium. Target bacteria binding aptamers are adsorbed on the surface of unmodified AuNPs to capture target bacteria, and the detection was accomplished by target bacteria-induced aggregation of the aptasensor which is associated as red-to-purple color change upon high-salt conditions. By employing anti-E. coli O157:H7 aptamer and anti-S. typhimurium aptamer, we developed a convenient and rapid approach that could selectively detect bacteria without specialized instrumentation and pretreatment steps such as cell lysis. The aptasensor could detect as low as 105 colony-forming units (CFU)/ml target bacteria within 20 min or less and its specificity was 100%. This novel method has a great potential application in rapid detection of bacteria in the near future.
Original language | English (US) |
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Article number | 658 |
Journal | Nanoscale Research Letters |
Volume | 7 |
DOIs | |
State | Published - 2012 |
Keywords
- Aptasensor
- AuNPs
- Colorimetric detection
- E. coli O157:H7
- Salmonella typhimurium
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics