Detection of Bacillus subtilis spores using peptide-functionalized cantilever arrays.
We move beyond antibody-antigen binding systems and demonstrate that short peptide ligands can be used to efficiently capture Bacillus subtilis (a simulant of Bacillus anthracis) spores in liquids. On an eight-cantilever array chip, four cantilevers were coated with binding peptide (NHFLPKV-GGGC) and the other four were coated with control peptide (LFNKHVP-GGGC) for reagentless detection of whole B. subtilis spores in liquids. The peptide-ligand-functionalized microcantilever chip was mounted onto a fluid cell filled with a B. subtilis spore suspension for approximately 40 min; a 40 nm net differential deflection was observed. Fifth-mode resonant frequency measurements were also performed before and after dipping microcantilever arrays into a static B. subtilis solution showing a substantial decrease in frequency for binding-peptide-coated microcantilevers as compared to that for control peptide cantilevers. Further confirmation was obtained by subsequent examination of the microcantilever arrays under a dark-field microscope. Applications of this technology will serve as a platform for the detection of pathogenic organisms including biowarfare agents.
Dhayal
Babita
B
Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
Henne
Walter A
WA
Doorneweerd
Derek D
DD
Reifenberger
Ronald G
RG
Low
Philip S
PS
D001412:Bacillus subtilis / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology; D015374:Biosensing Techniques / Q000379:methods*; D008024:Ligands; D036103:Nanotechnology / Q000379:methods; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D013171:Spores, Bacterial / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity
D008024:Ligands; D009842:Oligopeptides