Silver Eco-Solvent Ink for Reactive Printing of Polychromatic SERS and SPR Substrates.

Mavlavi Dustov,Alexander Polyakov,Efim Kolesnikov,Diana Golovina,Wolfgang Grünert,Dmitry Shtansky,Anastasia Grigorieva,Anastasia Goldt,Andrei Eliseev,Irina Sukhorukova

doi:10.3390/s18020521

Abstract

A new reactive ink based on a silver citrate complex is proposed for a photochemical route to surface-enhanced Raman spectroscopy active substrates with controllable extinction spectra. The drop-cast test of the ink reveals homogeneous nucleation of silver and colloid particle growth originating directly from photochemical in situ reduction in droplets, while the following evaporation of the deposited ink produces small nano- and micron-size particles. The prepared nanostructures and substrates were accurately characterized by electron microscopy methods and optical extinction spectroscopy. Varying the duration of UV irradiation allows tuning the morphology of individual silver nanoparticles forming hierarchical ring structures with numerous “hot spots” for most efficient Raman enhancement. Raman measurements of probe molecules of rhodamine 6G and methylene blue reached the largest signal enhancement of 106 by the resonance effects.

Highlights

Within the last decades, surface-enhanced Raman scattering (SERS) has been developed from a fantastical phenomenon [1] to a powerful analytical tool, capable of detecting single-molecules and identification of a great variety of analytes in environmental and biomedical samples [2]
We propose silver citrate complex as an ink component, which is appropriate for SERS substrate preparation and undergoes an easy-to-handle reduction induced by UV irradiation after the drop-cast or printing at the substrate
All the tension characteristics measured for silver compositions were in the reasonable range

Summary

Introduction

Surface-enhanced Raman scattering (SERS) has been developed from a fantastical phenomenon [1] to a powerful analytical tool, capable of detecting single-molecules and identification of a great variety of analytes in environmental and biomedical samples [2]. Polychromatic SERS substrates, i.e., substrates with multiple plasmon resonances in the visible range, are the most advanced and demanded products appropriate for different kinds of analytes. This is because they allow for the surface enhanced resonant Raman scattering (SERRS) effect, when the wavelength of a substrate plasmon resonance coincides with the wavelength of laser excitation and the maximum of the analyte optical absorption spectrum.

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Conclusion