Single-molecule spectroscopy using nanoporous membranes.
We describe a novel approach for optically detecting DNA translocation events through an array of solid-state nanopores that potentially allows for ultra high-throughput, parallel detection at the single-molecule level. The approach functions by electrokinetically driving DNA strands through sub micrometer-sized holes on an aluminum/silicon nitride membrane. During the translocation process, the molecules are confined to the walls of the nanofluidic channels, allowing 100% detection efficiency. Importantly, the opaque aluminum layer acts as an optical barrier between the illuminated region and the analyte reservoir. In these conditions, high-contrast imaging of single-molecule events can be performed. To demonstrate the efficiency of the approach, a 10 pM fluorescently labeled lambda-DNA solution was used as a model system to detect simultaneous translocation events using electron multiplying CCD imaging. Single-pore translocation events are also successfully detected using single-point confocal spectroscopy.
Chansin
Guillaume A T
GA
Institute of Biomedical Engineering, Imperial College London, South Kensington, SW7 2AZ, United Kingdom.
Mulero
Rafael
R
Hong
Jongin
J
Kim
Min Jun
MJ
DeMello
Andrew J
AJ
Edel
Joshua B
JB
D004247:DNA / Q000737:chemistry* / Q000235:genetics*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D044085:Microfluidics / Q000379:methods*; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D016062:Porosity; D013057:Spectrum Analysis / Q000379:methods*; D013499:Surface Properties; D014178:Translocation, Genetic / Q000235:genetics
D046911:Macromolecular Substances; D008567:Membranes, Artificial; D004247:DNA