Raman spectroscopy and SERS by using Ag-nano-wires for detecting 1,2,4-Triazole in aqueous phase

Abstract

In this work we showcase the experimental detection of high and low concentrations of the organic molecule 1,2,4-Triazole (124T) in the aqueous phase using a Coupled Optical Fibre Raman Spectrograph (COFRS) at an excitation wavelength of 785 ηm. Considering that 124T is a molecule used for producing pesticides, herbicides and antibacterial, hence its relevance. Accordingly, high concentrations (5 to 0.25 M) were prepared to be evaluated with COFRS in its typical configuration using vials constructed from borosilicate glass type 1. Whereas for detection of low concentrations (10 <-1>−1 to 10 <-6> M), COFRS was coupled to the Surface Enhanced Raman Spectroscopy (SERS) technique by using Ag-nanowires as substrates. After obtaining the different spectral peaks of the 124T and plotting the areas of each peak against the molar concentration of each solution, a linear trend of around R 2 =0.99578 and R 2 =0.99917 was observed for the high and low detection ranges, respectively. As a result, the two best equations to quantitatively decide the concentration of an unknown aqueous solution of 124T in both ranges are obtained. Therefore, this work presents a promising methodology suitable for detecting high and low concentrations and is already used for other molecules by COFRS-SERS coupling.