ABSTRACT
We report on the fabrication and single electron tunneling behaviour of large scale arrays of nanogap electrodes bridged by bisferrocene-gold nanoparticle hybrids (BFc-AuNP). Coulomb staircase was observed in the low temperature current-voltage curves measured on the junctions with asymmetric tunnel barriers. On the other hand, junctions with symmetric tunneling barrier exhibited mere nonlinear current voltage characteristics without discrete staircase. The experimental results agreed well with simulations based on the orthodox theory. The junction resistance showed thermally activated conduction behaviour at higher temperature. The overall voltage and temperature dependent results show that the transport behaviour of the large arrays of single particle devices obtained by a facile optical lithography and chemical etching process corresponds with the behaviour of single particle devices fabricated by other techniques like e-beam lithography and mechanical breaking methods.
Subject(s)
Electrons , Ferrous Compounds/chemistry , Gold/chemistry , Metal Nanoparticles/chemistry , Microarray Analysis/instrumentation , Computer Simulation , Equipment Design , Metallocenes , Microscopy, Scanning Tunneling , Microtechnology , Models, Biological , Models, Molecular , Nanocomposites/chemistryABSTRACT
An economical nanoarray method to electrically detect hybridization events is demonstrated. As a proof of concept, we fabricated a sensor for DNA sequencing, in which targets are oligonucleotides conjugated to gold nanoparticles. As a consequence of target-probe binding events, a conductive bridge forms between two electrodes, resulting in a quantized change in conductivity. This enables a robust detection of a few (down to single) hybridization events and can be potentially applied also to other binding events (like specific interactions between proteins, antibodies, ligands and receptors). Moreover, target amplification techniques (such as PCR) are no longer necessary.
