We developed the methods for fast detections of toxic food contaminations using nanotechnologies. As the first step, the single-molecule interactions between ricin and aptamers were investigated by atomic force spectroscopy and dynamic force spectroscopy. The aptamer we used here is a short ssDNA sequences with 38 nt. The detection limit was 20 pg/mL for the ricin in aqueous solution. The aptamer specifically interacted with ricin molecules, with the affinity of 6.8 10-4 s-1, which is very close to the affinity of the anti-ricin antibody. Aptamers have advantages over antibody, such as low cost, easier chemical modification, smaller size, and stable activity. The aptamer and surface modification methods showed high sensitivity for the detection of trace amounts of toxic contamination and can be used in other nano-scale devices such as surface plasmon resonance. The similar methods will be applied to other species, such as Salmonella, for versatile and high-throughput detections.

Single-molecule detection of toxic protein ricin using atomic force microscopy

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.