Four-probe electrical characterization of Pt-coated TMV-based nanostructures

Abstract

The electrical transport and structural properties of tobacco mosaic virus (TMV)-based nanostructures have been studied. Electroless deposition was used to coat the TMV outer surface with a 13 nm thick homogeneous Pt layer. SEM, TEM and electrical characterization of the obtained nanostructures has been performed. Using four independently controlled scanning tunnelling microscope tips we were able to perform four-point probe resistance measurements on linear virus assemblies and demonstrate the continuous nature of the metallic coating. The measured resistivity values of the virial nanowires exceeded the bulk value by 10-100 times; notwithstanding this the coated structure allowed high current densities, of the order of 10(5)-10(8) A cm(-2). The four-probe technique proved to be useful for analysing the electrical properties of bio-inorganic nanowires.

Near‐Bulk Conductivity of Gold Nanowires as Nanoscale Interconnects and the Role of Atomically Smooth Interface

“…The NWs of Pt, Au, and Cu were shown to have resistivities as high as 3, 7, 26 times of the corresponding bulk metal, respectively. [10,11,25] Twoand four-probe transport measurements on Au and Pt NWs made by axial solution growth [26][27][28] displayed resistivities from 10 [28] to as high as 100 times [26,27] higher than the bulk. These observations raise several basic questions related to nanoscale interconnects.…”

“…[27,28] One of the advantages of the MPSTM technique is the possibility of plotting resistance against sensing tip separation, allowing one to calculate the resistivity of NWs using several measurements. [26,29,36] Resistance versus probe separation data for the 92-nm and 185-nm diameter Au NWs are shown in Figure 2C, which correspond to resistivities of 2.19 AE 0.06 mV.cm and 2.1 AE 0.2 mV.cm, respectively, i.e. corresponding to bulk gold.…”

Synthesis of High‐Surface‐Area Platinum Nanotubes Using a Viral Template

“…[14][15][16][17][18] Furthermore, individual TMV particles have been shown to self-assemble (end to end) into longer filamentous structures [12,18,19] and allow the formation of nanoelectronic components. [14,18,20] Wet-chemical synthesis is the most often used process for TMV metallization. In a typical process, metal salt is added to the aqueous solution of TMV, and pH adjusted if necessary to allow metal ion to attach to the virus surface.…”

“…In a typical process, metal salt is added to the aqueous solution of TMV, and pH adjusted if necessary to allow metal ion to attach to the virus surface. Subsequent reduction of metal salt is carried out by adding a reductant such as dimethylamine borane (DMAB), [14,17,18] hydrazine, [16] or sodium hypophosphite. [17] The nanotube synthesis reported here is based on an alcoholdriven reduction of Pt salt in the presence of virus, which serves as a positive template.…”

“…The uniformity of obtained nanotubes is far greater than those obtained by reducing the Pt salt with common reductants, such as DMAB or hydrazine. [16,18] The electrical continuity of the metal coating is demonstrated using a two-probe electrical resistance measurement on an individual Pt-TMV nanotube.…”