Superhydrophobic Ag‐Decorated CuO Nanowire Arrays with Analyte‐Concentrating and Self‐Cleaning Binary Functions for Ultrasensitive and Recyclable Surface‐Enhanced Raman Scattering

Abstract

Surface‐enhanced Raman scattering (SERS) is considered a promising analytical technique for the detection of analytes. Considering the practical SERS detection, it is necessary to develop low‐cost, highly sensitive, and recyclable SERS‐active substrates. Here, a simple and flexible approach is proposed to fabricate a superhydrophobic Ag‐decorated CuO (named as CuO@Ag) nanowire array substrate with analyte‐concentrating and self‐cleaning binary functions for ultrasensitive and recyclable SERS detection. During this process, a superhydrophobic CuO@Ag nanowire array is made via fabrication of a CuO nanowire array by oxidizing and calcinating an ordered porous anodic aluminum oxide template on Cu foil, and following with Ag sputtering deposition on CuO nanowire array. Remarkably, this SERS substrate exhibits ultrasensitive SERS detection ability attributed to superhydrophobic plasmonic metal nanostructured arrays with high analyte‐concentrating ability and excellent photocatalytic capability due to this metal‐semiconductor composite nanostructure. These advantageous properties allow for SERS detection of malachite green with a limit of detection of 6.73 × 10−13 m and self‐cleaning via photodegradation of adsorbed analytes with visible‐light illumination. Consequently, it achieves recyclable SERS detection. This research demonstrates a simple and flexible approach for fabricating recyclable SERS‐active substrate, which expands the practical SERS applications in chemical and biological analysis, food safety, and healthcare.

Au Nanoparticles Decorated CoP Nanowire Array: A Highly Sensitive, Anticorrosive, and Recyclable Surface-Enhanced Raman Scattering Substrate

“…Liu and co-authors reported a Au-coated TiO 2 nanotube array and confirmed its high SERS activity and photocatalytic degradation for rhodamine 6G (R6G) . Deng et al fabricated a Ag-decorated CuO nanowire array substrate with analyte-concentrating and self-cleaning functions for sensitive SERS detection . Macias–Montero et al constructed Ag@ZnO-supported nanorods with application in the SERS detection of R6G .…”

“…20 Deng et al fabricated a Ag-decorated CuO nanowire array substrate with analyteconcentrating and self-cleaning functions for sensitive SERS detection. 21 Macias−Montero et al constructed Ag@ZnOsupported nanorods with application in the SERS detection of R6G. 22 However, these hybrid materials as SERS substrates have a series of problems, such as complicated preparation, limited sensitivity, and acid-intolerant properties.…”

Superhydrophobic 3D‐Assembled Metallic Nanoparticles for Trace Chemical Enrichment in SERS Sensing

“…Superhydrophobic Ag‐decorated CuO nanowire arrays were developed to enable ultrasensitive detection of Malachite Green molecules down to the sub‐picomolar level. [ 10 ] Nanostructured‐Au microisland arrays with wettability difference also demonstrated the ultrasensitive detection of femtomol Rhodamine 6G. [ 11 ] Nevertheless, the important feature of chip‐to‐chip reproducibility has not been investigated.…”

“…[11] Nevertheless, the important feature of chipto-chip reproducibility has not been investigated. [10,11] Therefore, sensitive and reproducible SERS substrates using large-scale manufacturing processes are strongly desired for quantitative sensing in real applications. Recently, efficient and broadband plasmonic absorbers, composed of self-assembled metal NPs on the nanoporous templates, have received extensive research efforts because they support strong plasmonic resonances in a broad spectral band and can easily be fabricated over large areas with no need of lithography process.…”

“…[3,4] To address this technical challenge, superhydrophobic surfaces were introduced for analyte enrichment, i.e., to concentrate and transfer analytes toward a specific position. [2,[5][6][7][8][9][10][11] In general, two strategies have been used to combine superhydrophobic surfaces with SERS-active elements (plasmonic nanostructures) for improved sensing performance. The first strategy employs aggregated random metal nanoparticles (NPs) with analytes on a superhydrophobic platform.…”