Shape controlled gold nanostructures on de-alloyed nanoporous gold with excellent SERS performance

Abstract

In this study, nanoporous gold (NPG) has been prepared by chemical de-alloying the Au based metallic glass precursor, Au 20 Cu 48 Ag 7 Pd 5 Si 20 (at.%), which was rapidly solidified from the melt in the form of ribbons. On the nanoporous gold, shape controlled gold nanostructures were electrodeposited by adjusting the applied potentials and deposition times. Using Rhodamine 6G (R6G) as probe molecule, the surface enhanced Raman scattering (SERS) activities with different Au nanostructures on nanoporous gold were compared. The electrodeposited Au dendritic nanostructures on NPG after 3000s exhibited strongest SERS effect and high reproducibility. Using this best SERS active substrate for melamine sensing, the detection limit of 10-7 M was achieved.

Estimation of Nanoporous Au Young’s Modulus from Serial Block Face-SEM 3D-Characterisation

“…Amorphous ribbons about 20 mm thick and 2 mm wide were obtained by melt spinning. The NP Au samples were prepared by dealloying amorphous ribbons in free corrosion conditions at 70 °C in an aqueous solution of 10 M HNO 3 and 0.5 M HF for 4 h [ 13 , 14 ].…”

Electrodeposition of Nanoporous Gold Thin Films

“…It is a corrosive solution such as an acid in the case of chemical dealloying, the constant potential for electrochemical dealloying and the nature of liquid metal medium and temperature are the crucial deciding factors in the emerging field of liquid metal dealloying [11]. Extensive investigations have demonstrated that nanoporous metals with 3-D bicontinuous structures fabricated by the dealloying method, has many active sites for the excitation of localized surface plasmons and can, therefore, serve as a potential substrate for practical surface-enhanced Raman scattering (SERS) application [23]. Unlike single-sized porous materials, a hierarchical (bimodal) porous structure can impart novel properties to the material wherein large pores can favor increased mass transport and small pores can impart high specific surface area [24].…”

Breaking Down SERS Detection Limit: Engineering of a Nanoporous Platform for High Sensing and Technology

“…In particular, nanoporous metals prepared by dealloying techniques have been receiving research interest and exhibit promising results in several fields of application: actuators [ 1 ], storage and conversion of energy [ 2 ], electrodes for electrocatalysis [ 3 , 4 ], electrochemical biosensors [ 5 , 6 , 7 ], and surface-enhanced Raman scattering [ 8 , 9 ]. Scattering enhancement has been ascribed to their high surface area and their morphology constituted in ligaments, ranging from tens to hundreds of nanometers, and basically composed of the noblest elements of the original alloy.…”