Micro Solid Phase Extraction Surface-Enhanced Raman Spectroscopy (μ-SPE/SERS) Screening Test for the Detection of the Synthetic Cannabinoid JWH-018 in Oral Fluid

Abstract

An analytical protocol based on surface-enhanced Raman spectroscopy (SERS) and aimed at the detection of toxicologically relevant concentrations of JWH-018 in oral fluid is presented for the first time. A DFT-supported in-depth vibrational characterization of the drug in the solid state and in solution was also performed, providing a body of literature for future spectroscopic work on the compound. A Langmuir adsorption model was used to derive quantitative parameters such as the affinity of JWH-018 for citrate-capped gold nanospheres as well as the LOD. The application of the implemented method to the analysis of extracts from fortified oral fluid samples demonstrates the feasibility of SERS as an alternative to current immunoassays as a screening tool for use in emergency room settings.

Methods in Raman spectroscopy for saliva studies – a review

“…[47] Moreover, for some substances, saliva may have a further advantage whereby the analytical sensitivity increases because the requisite substance has been orally ingested, as often evident with illicit drugs, however, analysis of oral residues, present in varying amounts, may impair quantitative analysis. [48] A positive correlation exists between multiple biomolecules detectable in serum and saliva due to the transfer of material via the salivary duct across a thin layer of epithelial cells by passive diffusion, active transport, or extracellular ultra-filtration. [9,20] Pfaffe et al [20] has compiled a comprehensive list of common biomolecules, which may be detected in both blood and saliva, and the clinically relevant ranges, highlighting indicators for oral and breast cancers as well as cardiovascular diseases, amongst others.…”

Recent advances in nano-photonic techniques for pharmaceutical drug monitoring with emphasis on Raman spectroscopy

“…Another approach to overcome matrix-related challenges is to combine sample pretreatment methods with the sensing platform [73,74,76,79,81,86,88,90]. For drug sensing in body fluids, several studies reported the combination of SERS and high-performance liquid chromatography (HPLC) [56].…”

“…Innovative SERS substrates [82,84] represent a breakthrough towards clinical application as they overcome difficulties related to proteins in body fluids. Several approaches combine sample pretreatment methods with SERS detection [73,74,76,79,81,86,88,90]. Some of the reported separation techniques result in extensive sample-to-result times (e.g.…”

“…Complex nanophotonic technologies also show potential for the tracing of illegal or adulterant drugs [73,74,85,87,89,[131][132][133][134][135]. With the developed techniques, drugs can even be traced in fingerprints [89] or in body fluids other than blood or urine such as saliva [87,90,136]. D'Elia et al recently reported about the extremely sensitive detection of cocaine in saliva via SERS, without any sample preparation [47].…”

Rapid Formation of Nanoclusters for Detection of Drugs in Urine Using Surface-Enhanced Raman Spectroscopy

“…Surface-enhanced Raman spectroscopy (SERS) has been used to detect a variety of molecules [ 6 , 7 , 8 , 9 , 10 ] because SERS-based methods only need a small sample and take a few seconds to achieve the multiplexed detection of molecules with high sensitivity. Many studies have reported the SERS detection of drugs, including cannabinoid [ 11 ], cocaine [ 12 , 13 , 14 , 15 , 16 , 17 ], flunitrazepam [ 18 ], alpha-methyltryptamine [ 19 ], heroin [ 17 , 20 ], ketamine [ 21 ], morphine [ 13 , 22 ], benzodiazepine [ 23 ], methamphetamine [ 13 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ], amphetamine [ 31 ], opioid [ 32 ], 3,4-methylenedioxymethamphetamine (MDMA) [ 25 , 27 , 28 , 33 ], 4-MMC [ 34 , 35 ], MC [ 25 ], barbiturate [ 36 ], and sulfa drugs [ 37 ]. While the plasmonic properties of nanostructured substrates or nanoparticles used for SERS measurements is critical for the sensitive detection of molecules, it has been demonstrated that sample pretreatment is also very important for the SERS detection of drugs in biological samples such as urine [ 14 , 25 , 27 ,…”