Eliminating irreproducibility in SERS substrates

Abstract

Irreproducibility in surface-enhanced Raman spectroscopy (SERS) due to variability among substrates is a source of recurrent debate within the field. It is regarded as a major hurdle towards the widespread adoption of SERS as a sensing platform. Most of the literature focused on developing substrates for various applications considers reproducibility of lower importance. Here, we address and analyse the sources of this irreproducibility in order to show how these can be minimised. We apply our findings to a simple substrate demonstrating reproducible SERS measurements with relative standard deviations well below 1% between different batches and days. Identifying the sources of irreproducibility and understanding how to reduce these can aid in the transition of SERS from the lab to real-world applications.

SERSbot: Revealing the Details of SERS Multianalyte Sensing Using Full Automation

“…As both sets of spectra show little variances, similarities between spectra are quantified using a Pearson correlation coefficient (PCC) r ( x , y ), which is an accepted and useful figure of merit for quantifying reproducibility and repeatability. 9 For the two spectra x and y , the PCC is defined as the ratio of the covariance cov ( x , y ) to the product of their standard deviations σ x σ y . This is estimated by calculating the empirical covariance and standard deviation between the first spectrum of each set and the subsequent samples ( Figure 2 c).…”

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

“…In addition, they show that sources of variance in substrates can be turned into tuning parameters, allowing for control in the sensitivities of the substrates when carefully characterized and controlled. [ 15 ]…”

“…In addition, they show that sources of variance in substrates can be turned into tuning parameters, allowing for control in the sensitivities of the substrates when carefully characterized and controlled. [15] Ikeda et al introduce a strategy for utilizing longrange surface plasmons (LRSPs) on a highly dampening platinum surface to study its electrochemical SERS properties. Electrochemical SERS was demonstrated using a Pt film electrode with a thickness of 30 nm and 632.8 nm excitation wavelength.…”

Multiplexed Liquid Biopsy and Tumor Imaging Using Surface-Enhanced Raman Scattering

“…It possesses unique features, such as its sensitivity and capacity for multiplexing, that are not found in other approaches, including enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), fluorescence in situ hybridization (FISH), fluorescence, and flow cytometry. The critical aspects of SERS-based approaches for the quantitative detection of biomarkers are related to their reproducibility, but several recent studies have addressed and analyzed the sources of this irreproducibility in order to show how these can be minimized [ 12 ].…”