Direct electrical single-molecule detection of DNA through electron transfer induced by hybridization

Abstract

Single-stranded DNA was utilized as a probe tip for single-molecule DNA detection. Hybridization of the DNA tip and target DNA induces electron tunneling through the resulting DNA duplex. It is demonstrated that the DNA tip allows not only genetic detection but also discovery of single-nucleotide polymorphisms at the single-molecule level.

One-by-one single-molecule detection of mutated nucleobases by monitoring tunneling current using a DNA tip

“…On the basis of the current value at the peak position, the conductance value of the dsDNA molecular junction created by the DNA tip and target ssDNA on the substrate was determined to be 48 nS, agreeing well with the previous study. 11 In addition, it was reported that the single-molecule conductance of 8-base-pair dsDNA having repeated GC sequences is 100 nS. 4 Given the fact that the G base has a relatively low highest occupied molecular orbital favorable for the charge transport, 5 the present results are in reasonable agreement with the literature.…”

“…1a). 11 In the present research, we demonstrate that the DNA tip allows for the direct detection of DNA mutations at the single-molecule level. The DNA tip was held stationary in close proximity to the target ssDNA, similar to the measurement of single-molecule conductance, 12,13 to monitor the tunneling current for the mutation detection.…”

“…The appearance of the plateaus indicates the formation of a molecular junction. As demonstrated in our previous study, 11 the DNA tip undergoes hybridization with the target ssDNA adsorbed onto a substrate. The resulting dsDNA bridges the gap between the metal tip and the substrate, and consequently induced electron transfer through this bridge.…”

Voltammetry and molecular assembly of G-quadruplex DNAzyme on single-crystal Au(111)-electrode surfaces – hemin as an electrochemical intercalator

“…Electronic conductivity of redox metalloproteins and metalloenzymes 34,[36][37][38][39]55,56 , and of double strand DNA-based molecules [11][12][13][16][17][18][19]57,58 immobilized at electrochemical interfaces have been explored comprehensively. Electronic conductivity of "non-canonical" DNA forms, quadruplexes in particular have also been addressed, but such reports have only begun to appear much more recently [27][28][29][30][31][32][33] , and with little if any direct approach to interfacial ; (c) surface immobilized G-quadruplexes finally offer perspectives for ultra-sensitive detection of metal ions [40][41][42] , complex biomolecules such as peptides [23][24][25][26][27][28][29][30] , and perhaps other analytes.…”

Effect of medium on charge transport properties of modified poly(dA)-poly(dT) DNA molecular wire

“…Another motivation to study charge transport is because understanding the electrical properties of DNA is important to determine possible applications of DNA as an electronic molecular device [10]. Recently, the charge transport phenomenon in DNA has been used to make a DNA biosensor that can detect other DNA molecules through hybridization and charge tunneling [11].…”