Determination of uric acid in synthetic urine by using electrochemical surface oxidation enhanced Raman scattering

Abstract

In this work, a new and easy methodology to determine uric acid in relevant samples using Raman spectroelectrochemistry is presented. The spectroelectrochemistry experiment is based on the in-situ formation of a suitable substrate that enables the enhancement of the Raman signal of an analyte during the oxidation stage of a silver electrode. This phenomenon is known as electrochemical surface oxidation enhanced Raman scattering (EC-SOERS) and has proved to be useful in quantitative analysis using disposable screen printed electrodes. The successful combination of EC-SOERS with PARAFAC analysis allows the determination of uric acid in a relevant complex sample avoiding the use of standard addition method and without using a baseline correction, which simplifies the application of such methodology in routine analysis.

Integrated EC-SERS Chip with Uniform Nanostructured EC-SERS Active Working Electrode for Rapid Detection of Uric Acid

“…Secondly, the uric acid EC-SERS spectra were measured in synthetic urine to simulate a more realistic sample. The synthetic urine was prepared according to the literature [8,23,28]. It has considered most of the components of the real urine matrix of healthy people (potential EC-SERS interference).…”

“…The LOD of uric acid can then be calculated by using the relation equation in Figure 9b. The resulting LOD is 8.7 × 10 −8 M. For the LOD of uric acid reported from other studies using EC-SERS technology, Lili Zhao et al [23] used multilayered Au/Ag as EC-SERS substrate for the quantitative detection of uric acid, and obtained a LOD approximately 1 × 10 −4 M. Sheila Hernandez et al [28] measured uric acid in synthetic urine by using electrochemical surface oxidation enhanced Raman scattering. The LOD reported in their study is 12.4 × 10 −6 M. Barbara L. Goodall et al [39] used the Ag nanoparticles deposited on silicon as a substrate to perform EC-SERS for detection of uric acid.…”

Double fingerprint characterization of uracil and 5-fluorouracil

“…This phenomenon is truly interesting, since its origin defies the classic theory of SERS, which suggest that Raman enhancement should disappear at anodic potentials due to the degradation of plasmonic properties [7 , 8] . Although the origin of EC-SOERS is still under discussion, it is clear that it provides a great reproducibility and selectivity in the enhancement of Raman signal of several analytes, which makes it a great method for the development of both qualitative and quantitative analytical methods [9][10][11] .…”

Electrochemical generation of surface enhanced Raman scattering substrates for the determination of folic acid

“…Raman-SEC is particularly interesting, since it allows us to take advantage of electrochemical surface enhanced Raman scattering (EC-SERS) and other phenomena like electrochemical surface oxidation enhanced Raman scattering (EC-SOERS), which have been successfully used for analysis [10,13,19]. It is noteworthy the capability of EC-SERS and EC-SOERS to perform determinations of molecules in complex matrices [20] thanks to the spectroscopic fingerprint provided by Raman spectroscopy. Moreover, electrochemistry is very useful for SERS analysis because it can be used to adsorb the target molecule on the electrode surface [21][22][23][24], increasing the Raman signal.…”