Microfluidics-Driven Fabrication of a Low Cost and Ultrasensitive SERS-Based Paper Biosensor

Abstract

Surface-enhanced Raman scattering (SERS) spectroscopy stands out due to its sensitivity, selectivity, and multiplex ability. The development of ready-to-use, simple, and low-cost SERS substrates is one of the main challenges of the field. In this paper, the intrinsic reproducibility of microfluidics technology was used for the fabrication of self-assembled nanoparticle structures over a paper film. The paper SERS substrates were fabricated by assembling anisotropic particles, gold nanostars (GNSs), and nanorods (NRs) onto paper to offer an extra enhancement to reach ultra-sensitive detection limits. A polydimethylsiloxane PDMS-paper hybrid device was used to control the drying kinetics of the nanoparticles over the paper substrate. This method allowed a high reproducibility and homogeneity of the fabrication of SERS substrates that reach limits of detection down to the picomolar range. This simple and low-cost fabrication of a paper-based sensing device was tested for the discrimination of different cell lineages.

Retracted Article: Synergistic action of star-shaped Au/Ag nanoparticles decorated on AgFeO2 for ultrasensitive SERS detection of a chemical warfare agent on real samples

“…The peak at 865 cm −1 corresponds to the aromatic–NO 2 scissor mode. 48 The SERS spectra of PE adsorbed on AgFeO 2 , Au/Ag NPs and AgFeO 2 @Ag/Au NPs (AFA-1) are shown in Fig. S4 †.…”

Stationary, Continuous, and Sequential Surface‐Enhanced Raman Scattering Sensing Based on the Nanoscale and Microscale Polymer‐Metal Composite Sensor Particles through Microfluidics: A Review

“…First, particlebased SERS sensing technique became more and more in the focus of interest for the detection of biomolecules or bioactive substances, drugs, and so on at low concentrations and measurements in microfluidic systems. [81][82][83][84][85] Second, metal/polymer composite microparticles were developed which are promising for the improvement of the sensitivity, re-use capability, and the handling of SERS-active particles for single-bead based sensor strategies. [31,86,87] Third, nanoparticles and special nanoparticle assemblies with special geometries were synthesized to achieve local strength of the electromagnetic field resulting in enhancements of the SERS effect.…”

Multiplexing Liquid Biopsy with Surface‐Enhanced Raman Scattering Spectroscopy

“…[ 104,105 ] Nevertheless, colloidal suspensions present some limitations related to the colloidal and optical stability and the lack of interaction between particles for generation of the so‐called hot‐spots (regions with an extra SERS enhancement due to the plasmon interaction of two particles). [ 106 ] In this line, the controlled self‐assembly of nanoparticles over different substrates or the design of hybrid (Figure 3c) materials having 3D networks of reproducible hot‐spots have been explored. [ 107 ]…”