Photoelectrochemical studies of DNA-tagged biomolecules on Au and Au/Ni/Au multilayer nanowires

Abstract

The use of nanowires (NWs) for labeling, sensing, and sorting is the basis of detecting biomolecules attached on NWs by optical and magnetic properties. In spite of many advantages, the use of biomolecules-attached NWs sensing by photoelectrochemical (PEC) study is almost non-existent. In this article, the PEC study of dye-attached single-stranded DNA on Au NWs and Au-Ni-Au multilayer NWs prepared by pulse electrodeposition are investigated. Owing to quantum-quenching effect, the multilayer Au NWs exhibit low optical absorbance when compared with Au NWs. The tagged Au NWs show good fluorescence (emission) at 570 nm, indicating significant improvement in the reflectivity. Optimum results obtained for tagged Au NWs attached on functionalized carbon electrodes and its PEC behavior is also presented. A twofold enhancement in photocurrent is observed with an average dark current of 10 μA for Au NWs coated on functionalized sensing electrode. The importance of these PEC and optical studies provides an inexpensive and facile processing platform for Au NWs that may be suitable for biolabeling applications.

A versatile synthesis method of dendrites-free segmented nanowires with a precise size control

“…The obtained Gaussian distributions display well defined peaks with average value (standard deviations) of 34.4 nm (2.1 nm) in nanowire diameter. These results correspond to a low dispersion of the nanowires sizes and translate an improved uniformity when compared with reported data in the literature [ 27 , 28 ]. After the PAA removal, the segmented nanowires were resuspended and the Cu etched away (Figure 3b ).…”