Queensland Fire and Emergency Services, Research and Scientific Branch, Brisbane, Australia.
Chemistry Department, University of Queensland, St Lucia, Brisbane, Australia.
J Forensic Sci. 2021 Mar;66(2):505-519. doi: 10.1111/1556-4029.14610. Epub 2020 Nov 2.
A handheld, spatially offset Raman spectroscopy (SORS) system was successfully used to obtain Surface-enhanced Raman Scattering (SERS) spectra of fentanyl under simulated field conditions. A series of aqueous fentanyl solutions were prepared with commercially available gold nanoparticle solution, at concentrations ranging from 0.003 to 1697 μM. These SERS spectra were then used to generate two concentration calibration models (via a plot of peak area (1026 cm ) versus concentration, and quantitative spectral decomposition using partial least squares (PLS1)). For both models, the relationship followed Langmuir adsorption and became non-linear at concentrations above ~0.2 μM, with a limit of detection (LOD) of approximately 3 nM. The same technique was successfully used to measure fentanyl in the presence of two common "cutting agents," heroin and glucose, at 1% and 2% fentanyl proportions (w/w). Fentanyl detection was successfully achieved, but mixture interference from the cutting agents prevented a calibration model being generated. Four fentanyl analogues were also investigated-butyrylfentanyl, furanylfentanyl, acetylfentanyl, and ocfentanyl. A concentration calibration model for each species was successfully generated, but differentiation from fentanyl proved more challenging, although several potential diagnostic peaks were identified. These results identified a pathway forward in using handheld equipment for the reliable detection of ultra-low concentrations of fentanyl and fentanyl analogues via SERS, even when mixed with diluents. However, quantitative detection is negatively impacted in the presence of heroin and glucose. This also provides a starting point for a SERS-based spectral library of fentanyl analogues, in combination with a range of different diluents.
一种手持式空间位移拉曼光谱（SORS）系统成功地用于在模拟现场条件下获取芬太尼的表面增强拉曼散射（SERS）光谱。使用市售的金纳米粒子溶液制备了一系列浓度范围为 0.003 至 1697 μM 的芬太尼水溶液。然后使用这些 SERS 光谱生成了两个浓度校准模型（通过峰面积（1026 cm ）与浓度的关系图，以及使用偏最小二乘法（PLS1）进行定量光谱分解）。对于这两个模型，关系遵循朗缪尔吸附，在浓度高于约 0.2 μM 时变得非线性，检测限（LOD）约为 3 nM。同样的技术成功地用于在 1%和 2%芬太尼比例（w/w）的情况下测量存在两种常见“切割剂”海洛因和葡萄糖的芬太尼。成功地检测到了芬太尼，但切割剂的混合物干扰阻止了校准模型的生成。还研究了四种芬太尼类似物-丁酰芬太尼、呋喃芬太尼、乙酰芬太尼和奥芬太尼。成功地为每种物质生成了浓度校准模型，但从芬太尼中进行区分更具挑战性，尽管确定了几个潜在的诊断峰。这些结果确定了一种通过 SERS 可靠检测超低浓度芬太尼和芬太尼类似物的手持式设备的前进道路，即使与稀释剂混合也是如此。然而，在存在海洛因和葡萄糖的情况下，定量检测受到负面影响。这也为基于 SERS 的芬太尼类似物光谱库提供了一个起点，结合一系列不同的稀释剂。
