“Rinse, Repeat”: An Efficient and Reusable SERS and Catalytic Platform Fabricated by Controlled Deposition of Silver Nanoparticles on Cellulose Paper

Abstract

Grafting metal nanoparticles (NPs) on flexible platforms is being increasingly attempted to advance their usage in the field of catalysis, sensing, energy storage, etc. However, anchoring NPs on substrates is nontrivial as it involves surface modification of the NPs and/or the substrate, which makes the whole process tedious. Here, we extend the classical “silver-mirror” reaction to unmodified filter paper achieving a controllable deposition of Ag NPs. The Ag NPs/filter paper thus obtained was employed as an enhanced Raman scattering (SERS) substrate achieving detection limits down to picomolar (10–12 M) and nanomolar (10–9 M) concentrations for rhodamine 6G and rhodamine B, with an enhancement factor (EF) of 1.42 × 1010 and 0.659 × 106, respectively. To check its usage for practical applications, the substrate was extended to detect trace amounts of illicit dyes used on common vegetables and contaminants in rain, pond, and tap water with excellent reproducibility. Moreover, the as-prepared Ag–paper can be directly employed for 4-nitrophenol reduction, which can be completely reduced to 4-aminophenol (4-AP) in a single step within seconds. The substrate can be reused several times over without any noticeable change in its catalytic activity. Finally, we studied the chemical transformation of 4-nitrophenol to 4-aminophenol by studying the concomitant spectral response, thereby integrating catalysis and SERS on a single substrate. This method thus provides a facile avenue to low-cost paper-based functional substrates for multimodal applications.

Towards practical and sustainable SERS: a review of recent developments in the construction of multifunctional enhancing substrates

“…Conversely, superhydrophobic self-cleaning enhancing substrates can typically be regenerated easily and rapidly by rinsing with water. [252][253][254][255] Inspired by nature, superhydrophobic enhancing substrates are typically composed of enhancing noble metal nanoparticles dispersed on the surface of micro-structures to mimic the surface structure of self-cleaning biomaterials, such as lotus leaves. In a typical display, Li, et al designed nonpinning superhydrophobic films with plasmonic hierarchical microscale and nanoscale surface structures produced by laser lithography as reusable SERS substrates (Figure 18A).…”

Flexible SERS substrates for hazardous materials detection: recent advances

“…The porosity of the paper (which is typically a few μm) will affect the retention of NPs on its surface. There are numerous approaches for the fabrication of paper-based SERS substrates reported in recent literature including physical vapor deposition 76,77 , dipping method 67,71 , in-situ growth of metal NPs 78,79 , hydrophilic wells by wax printing followed by drop-casting of the NPs 80 , pen-on-paper technique 73 , inkjet printing 72,81 , etc.. Some of these techniques of the fabrication of paper substrates, collated from a few recent research reports, is illustrated in Fig.…”

Self-sustainable and recyclable ternary Au@Cu2O–Ag nanocomposites: application in ultrasensitive SERS detection and highly efficient photocatalysis of organic dyes under visible light

“…In our previous work, we constructed noble metal/semiconductor composite SERS substrates on 2D polystyrene (PS) nanosphere arrays by magnetron sputtering and achieved highly sensitive SERS detection of various environmental pollutants 7,8 . However, these nanostructured SERS substrates exhibited several drawbacks, such as a complex synthesis, high cost, and a need for large-scale expensive equipment 9 . To reduce costs and realize practical application of SERS substrates, much work has focused on the preparation of SERS substrates immobilized on modified magnetic supports.…”