Attenuated total reflection‐cascading nanostructure‐enhanced Raman spectroscopy on flat surfaces: A nano‐optical design

Abstract

The surface‐enhanced Raman scattering (SERS) effect was discovered by Richard Van Duyne et al. in 1977. He and coworkers also first utilized an innovative strategy that used SERS to record spectra on such SERS‐inactive substrate surfaces as n‐gallium arsenide (100) surfaces, which were modified by silver nano‐islands. This nanostructure‐enhanced Raman spectroscopy on flat surfaces (NERSoFS) enabled such SERS applications to be expanded to a variety of materials by virtue of SERS‐active nanostructures such as Au or Ag nanoparticles and shell‐isolated nanoparticles. However, most of such systems, although yielding Raman spectra, produce rather low enhancements, especially when used to record spectra on flat surfaces of SERS‐inactive materials. In this work, along with the direction of Van Duyne's borrowing‐SERS strategy and on the basis of the strategy of cascading optical coupling, we consider a theoretically designed optical configuration, based on an attenuated total reflection‐cascading nanostructure to produce enhanced Raman spectroscopy (ATRc‐NERS) on flat surfaces. This system can effectively harvest the incident light, thereby boosting the local optical field of the incident light and also moderately increasing the radiation field of the Raman‐scattered signals. In this way, one can gain 1–2 additional orders of magnitude in Raman enhancement over present NERSoFS systems both on metallic and nonmetallic flat surfaces, which are otherwise SERS‐inactive. This ATRc‐NERS strategy can potentially be used to develop ultrasensitive and versatile tools for surface science, material science, catalysis, electrochemistry, and micro‐electronics and micro‐LED industries.

Advances of surface-enhanced Raman and IR spectroscopies: from nano/microstructures to macro-optical design

“…The structure can also be excited through the ATR prism/metal film/nanoparticle configuration as shown in Figs. 8e and 9a 53 . At the critical angle at which the SPP at the film/air interface is on resonance, the SERS intensity at the film surface with or without the coupled nanoparticles reaches the maximum (Fig.…”

“…Structures only supporting SPP cannot provide strong enough local field enhancement for SERS or SEIRA, however, coupled structures such as an Au thin film coupled with an Au nanoparticle can be built to support the SPP coupled with LSP for giant local field enhancement in the particle–substrate nanogap (Fig. 4d ) 52 , 53 .…”

“…8e ). Figure 8f–h shows several configurations with ATR prisms coupled with refractive or reflective objectives to support the excitation hollow cone 53 , 94 , 95 .

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“…To improve the sensitivity, as shown in Fig. 11e our group designed an ATR-cascading SHINERS (ATRc-SHINERS) optics based on an ATR-cascading nanostructure-enhanced Raman spectroscopy on flat surfaces 53 . The design of ATRc-SHINERS optics is based on the concept of cascading EM field from macro to nano scale.…”

Preface to the special issue dedicated to Professor Richard P. Van Duyne (1945–2019)

“…The additional enhancement for flat nonmetallic or metallic substrates is essential important for a wide array of practical applications. [19] 3 | APPLICATIONS Cialla-May, Popp, et al show an easy, rapid, and nondestructive method for SERS detection of a B 12 -containing enzyme of the respiratory chain in bacterial membranes. The specific detection of the tetrachloroethene reductive dehalogenase is helpful for monitoring the active dehalogenation processes of bacteria in a low oxygen environment.…”