Nanoimprinted Patterned Pillar Substrates for Surface-Enhanced Raman Scattering Applications

Abstract

A pragmatic method to deposit silver nanoparticles on polydopamine-coated nanoimprinted pillars for use as surface-enhanced Raman scattering (SERS) substrates was developed. Pillar arrays consisting of poly(methyl methacrylate) (PMMA) that ranged in diameter from 300 to 500 nm were fabricated using nanoimprint lithography. The arrays had periodicities from 0.6 to 4.0 μm. A polydopamine layer was coated on the pillars in order to facilitate the reduction of silver ions to create silver nucleation sites during the electroless deposition of sliver nanoparticles. The size and density of silver nanoparticles were controlled by adjusting the growth time for the optimization of the SERS performance. The size of the surface-adhered nanoparticles ranged between 75 and 175 nm, and the average particle density was ∼30 particles per μm(2). These functionalized arrays had a high sensitivity and excellent signal reproducibility for the SERS-based detection of 4-methoxybenzoic acid. The substrates were also able to allow the SERS-based differentiation of three types of bacteriophages (λ, T3, and T7).

Fe3O4@Graphene Oxide@Ag Particles for Surface Magnet Solid-Phase Extraction Surface-Enhanced Raman Scattering (SMSPE-SERS): From Sample Pretreatment to Detection All-in-One

“…When arriving the adsorption equilibrium, we covered another glass slide and collected all particles into one point using a small magnetic bar (Scheme 1e). The increased particle density can enhance the Raman signals of target species by the so-called "hot spots" effect 54 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 adsorption. k id indicates the diffusion rate constant, and C provides the thickness of the boundary layer.…”

Colorimetric Detection of Escherichia coli Based on the Enzyme-Induced Metallization of Gold Nanorods

“…coli BL21 was selected as model analyst, and bacteriophage T7 as the infecting phage were published previously. [ 30,31 ] This AuNR-based colorimetric assay combined the advantage of phage-based detection can specifi cally detect viable E. coli cells. As shown in Figure 4 b, the different blue shifts of the longitudinal LSPR peak were observed.…”

“…The bacterial cells were infected with T7 bacteriophages (phages) to release β‐gal for enzyme‐induced colorimetric detection. This phage‐based system is advantageous compared to an antibody‐based platform because of their specificity for target bacterial cells, their ability to distinguish between live and dead cells, and their low cost . Once released, the β‐gal induces a metallic silver deposition on the surface of AuNRs.…”

“…This phagebased system is advantageous compared to an antibody-based platform because of their specifi city for target bacterial cells, their ability to distinguish between live and dead cells, and their low cost. [28][29][30][31] Once released, the β-gal induces a metallic silver deposition on the surface of AuNRs. β-Gal activity and the blue shift of the longitudinal LSPR peak were directly related to the concentration of target E. coli cells.…”

Enhanced Self-Organized Dewetting of Ultrathin Polymer Blend Film for Large-Area Fabrication of SERS Substrate

“…The size of nanostructures and interparticle gap spacing strongly influence the property of SERS substrates1011. Although some flexible nanofabrication approaches like nanoimprinting lithograph1213, nanosphere lithograph1415 and electron or ion-beam lithography1617, have had great success in producing the SERS substrate with excellent properties, these methods are expensive, time-cost or not suitable for large-area application. These shortcomings limit the application of these methods.…”