One-pot platform for the collection and detection of nanoparticles: Flexible surface-enhanced Raman scattering (SERS) substrates with nano-pore structure

The potential of using flexible surface-enhanced Raman scattering (SERS) for single polymer nanoparticle detection has been recognized, however, most studies have used SERS substrates consisting of metal nanoparticles (MNPs) on hard materials, which have limited volume analysis and can easily be damaged. To overcome these issues, researchers have conducted recent studies on flexible or 3D-structured SERS substrates. This study used polydimethylsiloxane (PDMS) membranes for flexible substrates, Ag nanowires (AgNWs) to form nanopores, and PDMS-polyethylene glycol (PEG) block copolymer (BCP) to improve solvent application. The SERS substrates were able to detect rhodamine 6G (R6G) probes with a limit of detection (LOD) of 7.06 x 10-11 M, and were mechanically stable under various conditions such as bending, stretching, and torsion. The nano-pores of the SERS substrates could separate polystyrene (PS) particles from the solution, and filtered particles were visually distinguishable from AgNWs using a dark field microscope. The flexibility of the SERS substrates also allows for swab sampling of irregular surfaces. We were able to detect up to 10-10 M of crystal violet (CV) in the contaminated scallops and collect and detect PS in stainless-steel structures covered with 200 nm PS particles. Overall, the study shows the potential of using flexible SERS substrates for single polymer nanoparticle detection in various fields.

Automated summary

The study demonstrates the potential of flexible surface-enhanced Raman scattering (SERS) substrates for detecting single polymer nanoparticles. The use of polydimethylsiloxane (PDMS) membranes as flexible substrates, Ag nanowires (AgNWs) to create nanopores, and PDMS-polyethylene glycol (PEG) block copolymer (BCP) for solvent application improvement was investigated. The SERS substrates showed a limit of detection (LOD) of 7.06 x 10-11 M for rhodamine 6G (R6G) probes and exhibited mechanical stability under various conditions. Additionally, the substrates were able to separate polystyrene (PS) particles from a solution and visually distinguish them from AgNWs. The flexibility of the SERS substrates allowed for swab sampling of irregular surfaces and successful detection of crystal violet (CV) in contaminated scallops and PS in stainless-steel structures covered with PS particles.