Flexible and Highly Sensitive Sandwich-Structured PDMS with Silver Nanowires and Laser-Induced Graphene for Rapid Residue Detection

Abstract

Flexible surface-enhanced Raman scattering (SERS) substrates offer advantages over traditional rigid substrates for efficient extraction of target molecules from complex surfaces, which is critical for technical applications ranging from pesticide residue analysis to environmental pollutant monitoring and forensic science detection. Herein, flexible sandwich-structured silver nanowires with laser-induced graphene and polydimethylsiloxane (PDMS) (Ag NWs@LIG@PDMS) with high SERS activity, flexibility, and stability were prepared by a simple method. Its detection limit is as high as 10–14 M, which is significantly higher than that of silver nanowires embedded in PDMS (Ag NWs/PDMS) and silver nanowire adhesive PDMS (Ag NWs@PDMS) with bilayer structure, due to the efficacy of interlayer laser-induced graphene (LIG). Moreover, compared with similar structures, the sophisticated structural design of silver nanowires with laser-induced graphene embedded in PDMS (Ag NWs/LIG@PDMS) enables higher SERS activity. Apart from this, the Ag NWs@LIG@PDMS film maintains excellent SERS performance even under 10% tensile deformation and extreme operating temperature (−80 to 80 °C). In view of the above-mentioned advantages, SERS substrates have been successfully used for fast, efficient, low-cost, and nondestructive extraction and detection of peel surface and fingerprint residues in real scenes, providing avenues for molecular trace extraction and detection in food safety and forensics science.

Light-Initiated Imprinted Membrane-Based Biomimetic SERS Sensor toward Selective Detection of Trace MC-LR

“…The spectral peak will become sharp, and the signal is enhanced. 22 Although the PVDF-based SERS membrane can be considered as a promising sensor, the compositions of practical samples are complex. Therefore, to accurately detect MC-LR, it is necessary to avoid interference by other molecules.…”

“…Furthermore, after the membrane is combined with the metal particles, the vibration and strength of the chemical bond are reduced, and the energy level range of the electron in the orbital transition will be reduced. The spectral peak will become sharp, and the signal is enhanced . Although the PVDF-based SERS membrane can be considered as a promising sensor, the compositions of practical samples are complex.…”

A simple and convenient preparation of flexible paper-Ag NPs substrate for surface enhanced Raman spectroscopy

“…However, it is difficult to find a suitable SERS substrate because of the low reproducibility and the high variation of the SERS signal, which is affected by the conformation of the metal nanoparticles. To overcome these drawbacks of SERS, various methods have been developed to prepare suitable nanostructures, such as the construction of SERS substrates by electrochemical deposition [11], vapour deposition [12], ebeam lithography [13] and colloidal lithography [14] on conventional solid supports such as glass [15], silicon [16],zinc oxide (ZnO) [17,18],polymers [19,20],carbon nanotubes (CNTs) [21],anodic aluminium oxide (AAO) [22] and polydimethylsiloxane (PDMS) [23,24]. The substrates produced by these methods are rigid and have a high degree of reproducibility and sensitivity.…”