Rapid and Quantitative Determination of Sildenafil in Cocktail Based on Surface Enhanced Raman Spectroscopy

Abstract

Sildenafil (SD) and its related compounds are the most common adulterants found in herbal preparations used as sexual enhancer or man’s virility products. However, the abuse of SD threatens human health such as through headache, back pain, rhinitis, etc. Therefore, it is important to accurately detect the presence of SD in alcoholic beverages. In this study, the Opto Trace Raman 202 (OTR 202) was used as a surface-enhanced Raman spectroscopy (SERS) active colloids to detect SD. The results demonstrated that the limit of detection (LOD) of SD was found to be as low as 0.1 mg/L. Moreover, 1235, 1401, 1530, and 1584 cm−1 could be qualitatively determined as SD characteristic peaks. In a practical application, SD in cocktail could be easily detected using SERS based on OTR 202. Also, there was a good linear correlation between the intensity of Raman peaks at 1235, 1401, 1530, and 1584 cm−1 and the logarithm of SD concentration in cocktail was in the range of 0.1–10 mg/L (0.9822 < R2 < 0.9860). The relative standard deviation (RSD) was less than 12.7% and the recovery ranged from 93.0%–105.8%. Moreover, the original 500–1700 cm−1 SERS spectra were pretreated and the partial least squares (PLS) was applied to establish the prediction model between SERS spectra and SD content in cocktail and the highest determination coefficient (Rp2) reached 0.9856. In summary, the SD in cocktail could be rapidly and quantitatively determined by SERS, which was beneficial to provide a rapid and accurate scheme for the detection of SD in alcoholic beverages.

Rapid Quantitative Detection of Deltamethrin in Corydalis yanhusuo by SERS Coupled with Multi-Walled Carbon Nanotubes

“…In this experiment, the commercial Opto Trace Raman 202 (OTR202) substrate and the synthetic AuNP colloid substrate were used for detection, and the aggregation agents were (Opto Trace Raman 202) OTR103 and 1% NaCl solution, respectively. OTR202 has been proven to be an effective SERS active substrate, which can be used to detect and analyze a variety of substances [ 20 , 37 ]. From Figure 3 A–C, it was found that the enhancement effect of AuNPs at peaks of 559 cm −1 and 999 cm −1 was significantly better than that of OTR202.…”

Recent Developments in Surface-Enhanced Raman Spectroscopy and Its Application in Food Analysis: Alcoholic Beverages as an Example

“…Compared with the previous research with LODs of 1 [ 159 ], 1.63, and 2.20 mg/L [ 160 ], the LOD of sildenafil in this study was improved greatly. Lin et al [ 161 ] also introduced Opto Trace Raman 202 (OTR 202) as an active colloidal surface enhanced Raman spectroscopy (SERS) for the rapid quantitative determination of Sildenafil (SD) in alcoholic beverages, and the detection limit was 0.1 mg/L. Thus, SERS can be used for the rapid and quantitative determination of sildenafil in complex alcoholic beverages.…”

Insights into chemometric algorithms for quality attributes and hazards detection in foodstuffs using Raman/surface enhanced Raman spectroscopy

“…Any substance which is added to the food to enhance its appearance and its addition to any foodstuff is not allowed by the authorities is termed illicit or illegal. SERS and Raman spectroscopies have been used in conjunction with multivariate calibration for detecting such illicit additives (Bedward et al., 2019; Chen et al., 2011; Cheng & Dong, 2011; Cheung et al., 2010; Dhakal et al., 2016; Di Anibal et al., 2012; Gao et al., 2015; Haughey et al., 2015; He et al., 2015; Hu & Lu, 2016; Hu et al., 2015; Karunathilaka et al., 2017; Karunathilaka et al., 2018; Lin et al., 2019; Lin et al., 2008; Liu et al., 2010; Monago‐Maraña et al., 2019; Ou et al., 2017; Ryder et al., 1999; Xiong et al., 2017). Melamine is deliberately introduced to increase the content of protein foodstuff and has been widely studied in foodstuffs among the illicit additives using SERS/Raman chemometrics approach (Cheng & Dong, 2011; Hu & Lu, 2016; Hu et al., 2015; Karunathilaka et al., 2017; Lin et al., 2008; Liu et al., 2010; Xiong et al., 2017).…”