Distinct Mechanisms of DNA Sensing Based on N‐Doped Carbon Nanotubes with Enhanced Conductance and Chemical Selectivity

Abstract

N-doped capped carbon nanotube (CNT) electrodes applied to DNA sequencing are studied by first-principles calculations. For the face-on nucleobase junction configurations, a conventional conductance ordering is obtained where the largest signal results from guanine according to its high highest occupied molecular orbital (HOMO) level, whereas for the edge-on counterparts a distinct conductance ordering is observed where the low-HOMO thymine provides the largest signal. The edge-on mode is shown to operate based on a novel molecular sensing mechanism that reflects the chemical connectivity between N-doped CNT caps that can act both as electron donors and electron acceptors and DNA functional groups that include the hyperconjugated thymine methyl group.

Recent progress in atomistic simulation of electrical current DNA sequencing

“…3g). We have also shown that the charged defect states can provide a much enhanced chemical sensitivity (Kim et al 2014).…”

“…( 4)] at long gap distances, and leads to two completely different sequencing protocols (Fig. 5c) (Kim et al 2014). Particularly, we have shown that the novel sequencing mode of the latter large-gap distance case results from the different number and arrangement of chemical functional groups in the four nucleobases (C=O, NH3, and CH3) and the ability of the substitutionally-doped nitrogen in sp 2 carbon network to act both as an electron acceptor and a donor.…”

“…Finally, note that the four nucleobases are distinguishable in terms of the number and arrangement of chemical functional groups (NH2, CO, and CH3). Therefore, we can expect that utilizing the functional group-specific charge transfer and associated differences in chemical connectivity with electrodes 2 / 1  could also lead to a novel DNA sequencing mechanism (Kim et al 2014).…”

“…Since then, proof-of-principles experiments using Au electrodes have been successfully carried out (Chang et al 2010;Huang et al 2010;Ohshiro et al 2012;Tsutsui et al 2010). The employment of novel non-metal low-dimensional materials such as CNTs (Chen et al 2012;Kim et al 2014;Meng et al 2006;Meunier and Krstić 2008;Sadeghi et al 2014a), graphene (Ahmed et al 2012;Postma 2010;Prasongkit et al 2011Prasongkit et al , 2013, GNRs (Ahmed et al 2014b;Avdoshenko et al 2013;Cho et al 2011;Girdhar et al 2013Girdhar et al , 2014He et al 2011;Jeong et al 2013;Min et al 2011;Nelson et al 2010;Rajan et al 2014;Rezapour et al 2014;Saha et al 2011;Shenglin et al 2014;Zhang et al 2014;Zhao et al 2012), and other low-dimensional materials were also first proposed by theoreticians (Amorim and Scheicher 2014;Farimani et al 2014;He et al 2014;Sadeghi et al 2014a;Sadeghi et al 2014b;Thomas et al 2014), and along this line significant experimental advances are currently being made (Chen et al 2013;Garaj et al 2010;Merchant et al 2010;Schneider et al 2010;Traversi et al 2013).…”

Functionalized carbon nanotube electrodes for controlled DNA sequencing

“…55 Furthermore, N-doped CNTs have been found to be very effective for DNA sequencing. [56][57][58] Moreover, such low-dimensional CNTs have an atomically thin structure (chemical and physical) and unique electrical transport properties, [59][60][61][62][63][64][65] which can allow the individual iden-tication of DNA nucleotides based on in-plane transverse transmission and current signals, and may accomplish singlenucleobase resolution with enhanced control. Thus, to realize the potential of solid-state DNA sequencing on low-dimensional materials, to enable the reading of nucleotides at the singlemolecule level, and also to enhance the readout time, a high-delity control of ssDNA translocation still needs to be accomplished.…”