Large-area, uniform and low-cost dual-mode plasmonic naked-eye colorimetry and SERS sensor with handheld Raman spectrometer

TL;DR

This paper introduces FlexBrite, a large-area, uniform, low-cost plasmonic nanomushroom substrate that enables dual-mode naked-eye colorimetry and SERS detection, suitable for rapid chemical and biological analysis with handheld devices.

Contribution

The development of a wafer-scale, plastic-based nanomushroom substrate with high uniformity and dual-mode sensing capabilities for both SERS and colorimetry.

Findings

SERS enhancement factor of 10^8 in dry state and 4.81×10^8 in wet state.

Detection of biotin-streptavidin interaction using both SERS and colorimetry.

Trace methamphetamine detection in water with handheld Raman spectrometer.

Abstract

We demonstrated a highly sensitive, waferscale, highly uniform plasmonic nanomushroom substrate based on plastic for nakedeye plasmonic colorimetry and surface enhanced Raman spectroscopy (SERS). We gave it the name FlexBrite. The dualmode functionality of FlexBrite allows for label-free qualitative analysis by SERS with an enhancement factor (EF) of 10^8 and labelfree quantitative analysis by naked eye colorimetry with a sensitivity of 611 nm RIU-1. The SERS EF of FlexBrite in the wet state was found to be 4.81 X 10^8, 7 times stronger than in the dry state, making FlexBrite suitable for aqueous environments such as microfluid systems. The labelfree detection of biotin streptavidin interaction by both SERS and colorimetry was demonstrated with FlexBrite. The detection of trace amounts of the narcotic drug methamphetamine in drinking water by SERS was implemented with a handheld Raman spectrometer and FlexBrite. This plastic based dual-mode nano-mushroom substrate has the potential to be used as a sensing platform for easy and fast analysis in chemical and biological assays.