One-Step Synthesis of Au-Ag Nanowires through Microorganism-Mediated, CTAB-Directed Approach.

Luhang Xu,Huimei Chen,Qingbiao Li,Dengpo Huang,Tareque Odoom-Wubah,Xiaoling Jing,Jiale Huang

doi:10.3390/nano8060376

Luhang Xu, Huimei Chen + Show 5 more

Open Access

https://doi.org/10.3390/nano8060376

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Abstract

Synthesis and applications of one dimensional (1D) metal nanostructures have attracted much attention. However, one-step synthesis of bimetallic nanowires (NWs) has remained challenging. In this work, we developed a microorganism-mediated, hexadecyltrimethylammonium bromide (CTAB)-directed (MCD) approach to synthesize closely packed and long Au-Ag NWs with the assistance of a continuous injection pump. Characterization results confirmed that the branched Au-Ag alloy NWs was polycrystalline. And the Au-Ag NWs exhibited a strong absorbance at around 1950 nm in the near-infrared (NIR) region, which can find potential application in NIR absorption. In addition, the Au-Ag NWs showed excellent surface-enhanced Raman scattering (SERS) enhancement when 4-mercaptobenzoic acid (MBA) and rhodamine 6G (R6G) were used as probe molecules.

Highlights

Synthesis of one dimensional (1D) nanostructures has been in the limelight in the past decade [1,2]
Metal NWs have excellent dimensional effects, and they are able to form more complex nanoscale structures [4,5,6]. In contrast to their monometallic counterparts, bimetallic NWs are generally synthesized through galvanic replacement reactions in which the second metal precursor is reduced by monometallic NWs pre-synthesized from the first metal precursor [7]
We described a one-step microorganism-mediated, surfactant-directed approach to bimetallic AuPd nanoflowers in the presence of cetyltrimethylammonium chloride (CTAC) at room temperature [7]

Summary

Introduction

Synthesis of one dimensional (1D) nanostructures has been in the limelight in the past decade [1,2]. Metal NWs have excellent dimensional effects, and they are able to form more complex nanoscale structures [4,5,6]. In contrast to their monometallic counterparts, bimetallic NWs are generally synthesized through galvanic replacement reactions in which the second metal precursor is reduced by monometallic NWs pre-synthesized from the first metal precursor [7]. Instead of CTAC, a microorganism-mediated, hexadecyltrimethylammoniumbromide (CTAB)-directed (MCD) approach was expanded to one-step synthesis of Au-Ag NWs. chloroauric acid (HAuCl4) and silver nitrate (AgNO3) were selected as metal precursors, while ascorbic acid (AA) was selected as reductant. The as-obtained Au-Ag-NW/PPC nanocomposites can be directly used for SERS detection of some probe molecules

Experimental Materials

Synthesis of Au-Ag NWs

Characterization of Au-Ag NWs

Optical Property of Au-Ag NWs

Conclusions