A Rapid Detection Method for On-site Screening of Estazolam in Beverages with Au@Ag Core-shell Nanoparticles Paper-based SERS Substrate

Abstract

Estazolam (EST) is a common sedative-hypnotic drug with a risk of abuse. Therefore, rapid on-site detection of EST is necessary to control the abuse of EST. In this paper, a fast, simple, and sensitive method is demonstrated for the detection of EST in both water and beverages that use surface-enhanced Raman spectroscopy (SERS) techniques. Au @Ag core-shell nanoparticles (NPs) assembled on the filter paper as a SERS substrate exhibit good applicability and practicality. At the same time, density functional theory (DFT) is used to assign the vibration mode of the EST molecules, which guides for subsequent experiments. The lowest detectable concentration of EST in aqueous solution can be as low as 5 mg/L, and signal uniformity is excellent (RSD687 = 5.56%, RSD1000 = 4.35%). In addition, EST components artificially added to orange juice and pomegranate juice can be effectively detected by simple pretreatment with a minimum detection concentration as low as 10 mg / L. Therefore, the use of Au@Ag core-shell nanoparticles paper-based SERS substrate provides a quick and easy method for the detection of illegally added drugs in beverages.

Portable Raman spectroscopy applied to the study of drugs of abuse

“…For quantitative analysis of benzodiazepines in alcoholic solutions, an analytical curve was prepared using alcoholic solutions of cachaça adulterated with bromazepam to 11 concentration levels (0–3.19 mg ml −1 ). In Figure 9, the Raman spectra are reported, which have bands defined in 881, 1048, 1089, 1276, and 1456 cm −1 , characteristic of alcoholic matrixes [66,67]. The Raman spectra of the solutions at higher concentrations (from 2.55 to 3.19 mg ml −1 ) present broad bands of low intensity in the ranges from 1227 to 1407 cm −1 and 1581 to 1753 cm −1 , similar to those observed in alcoholic solutions adulterated with alprazolam and diazepam (Figure 8A).…”

“…Figure 8A shows the Raman spectra of solutions of pure alcoholic beverages and those adulterated with tablets of 3.19 mg ml −1 alprazolam and diazepam. The Raman spectra for pure alcoholic solutions have bands at 881, 1048, 1089, 1276, and 1456 cm −1 , which are characteristics of alcoholic matrixes [6,65–67]. The Raman spectra collected for adulterated alcoholic solutions of rum, gin, and vodka have broad bands of low intensity from 1227 to 1407 cm −1 and 1581 to 1753 cm −1 , which indicate disturbance of the spectral profile due to the presence of the adulterants.…”

“…Previously, Ali and Edwards [66], using Raman spectroscopy with portable instrumentation, laser excitation of 785 nm, and a power of 37 mW, reported the visual detection of the flunitrazepam pattern in the lowest concentration under study (0.01% [m/v]) in aqueous and alcoholic solutions from gin, rum, and vodka. Sha et al [67] developed a fast and sensitive method for the detection of estazolam in aqueous solutions by Surface enhanced Raman spectroscopy, SERS, using portable instrumentation (laser excitation of 785 nm and 25% power [75 mW]), which allowed the detection of concentrations up to 5 mg ml −1 .…”

“…I G U R E 8 (A) Raman spectra of pure alcoholic solutions adulterated with alprazolam tablets and diazepam. (B) Scores graph and (C and D) PC1 and PC2 loadings [Color figure can be viewed at wileyonlinelibrary.com]have bands defined in 881, 1048, 1089, 1276, and 1456 cm −1 , characteristic of alcoholic matrixes[66,67]. The Raman spectra of the solutions at higher concentrations (from 2.55 to 3.19 mg ml −1 ) present broad bands of low intensity in the ranges from 1227 to 1407 cm−1 …”

“…37 mW, reported the visual detection of the flunitrazepam pattern in the lowest concentration under study (0.01% [m/v]) in aqueous and alcoholic solutions from gin, rum, and vodka. Sha et al[67] developed a fast and sensitive method for the detection of estazolam in aqueous solutions by Surface enhanced Raman spectroscopy, SERS, using portable instrumentation (laser excitation of 785 nm and 25% power [75 mW]), which allowed the detection of concentrations up to 5 mg ml −1 . Therefore, Raman spectroscopy by portable instrumentation associated with the PCA and CARSPLS methods can be used for the qualitative and quantitative analysis of alcoholic solutions adulterated.…”