微流體樣品處理元件結合金奈米團簇用於卡西酮毒咖啡包現場檢測

Abstract

本研究開發了一步驟攜帶式裝置用於檢測毒品卡西酮，將過濾、萃取及離子選擇之前處理步驟整合於微流體晶片內並結合側層流試片應用於複雜基質毒咖啡包之現場即時檢測。檢測平臺透過微流體純化晶片整合樣品前處理所需的繁瑣步驟，包含樣品過濾、被動式微混合器進行液液萃取及陽離子交換膜進行離子選擇，以達到複雜樣品的純化，從而降低基質對檢測結果的干擾。平臺採用牛血清白蛋白 (Bovine serum albumin; BSA) 作為配體 (Ligands) 合成出的金奈米團簇 (BSA-AuNCs) 作為檢測探針，並結合側層流試片進行檢測。BSA-AuNCs由於尺寸較小 (< 2 nm)，在最高佔據分子軌域 (High Occupied Molecular Orbital; HOMO) 及最低未占分子領域 (Lowest Unoccupied Molecular Orbital; LUMO) 間會有類似分子的電子躍遷，並釋放出紅色的螢光。此種螢光特性使其作為檢測探針時，具有較靈敏且穩定的檢測效果，並僅需透過肉眼根據其螢光訊號強度即可進行結果判讀。卡西酮中的苯酮結構為良好的電子受體，具有較高的電子親和力。卡西酮將誘使BSA-AuNCs產生電子轉移，使BSA-AuNCs內部電子躍遷的能量產生變化。此能量變化導致BSA-AuNCs在經吸收特定波段光能後，其釋放的光能量也隨之改變，因而產生螢光淬滅。最後透過光強度偵測晶片來定量卡西酮濃度並達到現場檢測。本研究之檢測平臺對卡西酮類似物具有高選擇性，且可於12分鐘內完成卡西酮類毒咖啡包之純化及檢測，檢測線性範圍為0.5-5 mM，最低檢測極限為0.35 mM。最後，我們使用20個真實案例對系統的實用性進行了測試，並且能透過檢測系統中的閾值 (Threshold value)，成功分辨出卡西酮類毒品咖啡包。我們期望此快速、易操作、低成本之卡西酮類毒品檢測平臺能提供給第一線執法人員，從而有效減少卡西酮類毒品氾濫。

In this work, we developed a one-step portable device for detecting the drug cathinone. This technique integrates traditional pretreatment methods, such as filtration, extraction, and ion selection, onto a microfluidic chip and a lateral flow assay for on-site detection. This detection device requires no multiple steps for sample pretreatment, thereby achieving purification and reducing matrix interference. Bovine serum albumin (BSA) was modified on gold nanoclusters (AuNCs) to create detection probes (BSA-AuNCs), which were used in a lateral flow assay. Due to their small size (< 2.0 nm), BSA-AuNCs exhibit molecular-like electron transitions between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), emitting red fluorescence. The phenyl-ketone structure in cathinone acts as a superior electron acceptor due to its high electron affinity, inducing electron transfer in BSA-AuNCs. These energy changes alter the emitted light energy of BSA-AuNCs after absorbing specific wavelengths of light, resulting in fluorescence quenching. This approach enables efficient quantification of cathinone through light-intensity differences. The detection device demonstrates high sensitivity and selectivity for cathinone analogs, with a linear range of 0.5-5 mM and a detection limit of 0.35 mM. We can complete the purification and detection of cathinone-containing coffee packets within 12 minutes. To demonstrate the device's practicality, we tested 20 real cases and successfully distinguished cathinone-containing coffee packets using the proposed threshold value in the detection system, showing that the device can be used by frontline officers to curb the proliferation of cathinone drugs.