Solid-state nanopores and nanopore arrays optimized for optical detection.
While conventional solid-state nanopore measurements utilize ionic current, there is a growing interest in alternative sensing paradigms, including optical detection. However, a limiting factor in the application of optical schemes in particular is the inherent background fluorescence created by the solid-state membrane itself, which can interfere with the desired signal and place restrictions on the fluorophores that can be employed. An ideal device would incorporate a localized reduction in membrane fluorescence using a method that can be integrated easily with the nanopore fabrication process. Here, we demonstrate that in addition to forming nanopores and nanopore arrays, a focused helium ion beam can be used to reduce the fluorescence of a conventional silicon nitride membrane controllably. The reduction in background produces low-fluorescence devices that can be used for optical detection of double-strand DNA, as well as for conventional resistive pulse sensing. This approach is used to identify the translocation of short single-strand DNA through individual nanopores within an array, creating potential for a massively-parallel detection scheme.
Joint School of Nanoscience and Nanoengineering, University of North Carolina Greensboro, Greensboro, NC 27401, USA.
Furat
F
Sawafta
Bason
B
Clancy
Autumn T
AT
Carlsen
Martin
M
Huber
Adam R
AR
Hall
D015374:Biosensing Techniques / Q000379:methods; D003217:Conductometry / Q000379:methods*; D004279:DNA, Viral / Q000032:analysis* / Q000737:chemistry / Q000235:genetics*; D004553:Electric Conductivity; D058608:Nanopores / Q000648:ultrastructure*; D017655:Silicon Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*
D004279:DNA, Viral; D017655:Silicon Compounds; C032734:silicon nitride