TY - JOUR
T1 - Chemical recognition and binding kinetics in a functionalized tunnel junction
AU - Chang, Shuai
AU - Huang, Shuo
AU - Liu, Hao
AU - Zhang, Peiming
AU - Liang, Feng
AU - Akahori, Rena
AU - Li, Shengqin
AU - Gyarfas, Brett
AU - Shumway, John
AU - Ashcroft, Brian
AU - He, Jin
AU - Lindsay, Stuart
PY - 2012/6/15
Y1 - 2012/6/15
N2 - 4(5)-(2-mercaptoethyl)-1H-imidazole-2-carboxamide is a molecule that has multiple hydrogen bonding sites and a short flexible linker. When tethered to a pair of electrodes, it traps target molecules in a tunnel junction. Surprisingly large recognition-tunneling signals are generated for all naturally occurring DNA bases A, C, G, T and 5-methyl-cytosine. Tunnel current spikes are stochastic and broadly distributed, but characteristic enough so that individual bases can be identified as a tunneling probe is scanned over DNA oligomers. Each base yields a recognizable burst of signal, the duration of which is controlled entirely by the probe speed, down to speeds of 1nms 1, implying a maximum off-rate of 3s 1 for the recognition complex. The same measurements yield a lower bound on the on-rate of 1M 1s 1. Despite the stochastic nature of the signals, an optimized multiparameter fit allows base calling from a single signal peak with an accuracy that can exceed 80% when a single type of nucleotide is present in the junction, meaning that recognition-tunneling is capable of true single-molecule analysis. The accuracy increases to 95% when multiple spikes in a signal cluster are analyzed.
AB - 4(5)-(2-mercaptoethyl)-1H-imidazole-2-carboxamide is a molecule that has multiple hydrogen bonding sites and a short flexible linker. When tethered to a pair of electrodes, it traps target molecules in a tunnel junction. Surprisingly large recognition-tunneling signals are generated for all naturally occurring DNA bases A, C, G, T and 5-methyl-cytosine. Tunnel current spikes are stochastic and broadly distributed, but characteristic enough so that individual bases can be identified as a tunneling probe is scanned over DNA oligomers. Each base yields a recognizable burst of signal, the duration of which is controlled entirely by the probe speed, down to speeds of 1nms 1, implying a maximum off-rate of 3s 1 for the recognition complex. The same measurements yield a lower bound on the on-rate of 1M 1s 1. Despite the stochastic nature of the signals, an optimized multiparameter fit allows base calling from a single signal peak with an accuracy that can exceed 80% when a single type of nucleotide is present in the junction, meaning that recognition-tunneling is capable of true single-molecule analysis. The accuracy increases to 95% when multiple spikes in a signal cluster are analyzed.
UR - http://www.scopus.com/inward/record.url?scp=84861328703&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84861328703&partnerID=8YFLogxK
U2 - 10.1088/0957-4484/23/23/235101
DO - 10.1088/0957-4484/23/23/235101
M3 - Article
C2 - 22609769
AN - SCOPUS:84861328703
VL - 23
JO - Nanotechnology
JF - Nanotechnology
SN - 0957-4484
IS - 23
M1 - 235101
ER -