Electrochemical analysis of tyramine using PEDOT:PSS/AuNP/1-methyl-4-mercaptopyridium modified screen printed carbon electrode sensor in conjunction with molecularly imprinted polymer solid phase extraction

[[abstract]]摘要 飲食當中含大量乾酪素(tyramine)的食物十分常見，如起司、優葛。而乾酪素的代謝主要由人體腸道中的單胺基酸氧化酶(monoamine oxidase，簡稱MAO)負責，其主要功能為分解人體過多的單氨酸(例如:乾酪素、多巴胺)，避免過多單氨酸轉換為正腎上腺素(norepinephrine)而造成高血壓，嚴重時甚至失去性命。而具心理疾病的病患常會服用含有單胺基酸氧化酶抑制劑(monoamine oxidase inhibitors，簡稱MAOI) 的藥物或鎮靜劑來緩衝其病狀(例如:憂鬱症)；如果服用含MAOI藥物的同時攝入含乾酪素的食物，則可能會引發嚴重的副作用，例如頭痛、心跳加速、高血壓、心律不整。因此研發快速且高靈敏的方法檢測人體血液以及食物中所含乾酪素濃度是相當重要的課題。本研究利用網版印刷電極修飾導電高分子PEDOT:PSS複合材料，再利用電鍍上金奈米粒子之硫-金鍵特性，將1-甲基-4-吡啶硫醇修飾在工作電極表面。偵測反應於鹼性溶液環境中進行。將具有正電性的電極與負電荷的乾酪素分子相互吸引產生錯合，在本實驗的偵測範圍內，以微分脈衝伏安法量測其乾酪素之氧化電流，以得知血清樣品中乾酪素的濃度。此外，本實驗也利用分子印跡高分子的專一性技術，將合成出來的分子印跡高分子粉體製成管柱，萃取血清中所含的乾酪素分子，以利於除去在電化學偵測時干擾物所產生的訊號。本實驗方法有極佳的電化學偵測濃度線性範圍1×10-7～5×10-9 mol / L，(R2 = 0.9927)，偵測極限為1.17×10-9 mol / L。[[abstract]]Abstract Tyramine exists abundantly in dairy products such as cheese and yogurt; which is an indirectly acting sympathomimetic amine. Tyramine is largely inactivated by metabolism to catalyzed by monoamine oxidase (MAO) enzymes located in the liver, gut, and sympathetic nerves. The pressor action of tyramine was found to be dramatically potentiated in patients who take cheese while receiving MAO inhibitors (MAOI). This “cheese-reaction” restricts the drug use in the treatment of depression. High blood tyramine concentration may lead to high blood pressure due to the increase of norepinephrine. This phenomenon is commonly seen in people with depression or administrated with monoamine oxidase inhibitor. Therefore the measurement of serum tyramine concentration becomes critical. In this study, we detected serum tyramine concentration by molecular imprinted polymers (MIP) and modified screen printed carbon electrodes (SPCE). The electrodes were modified with PEDOT/PSS and gold nanoparticles (PEDOT/PSS/AuNP) to enhance the conductivity. The electrode was further modified with positively charged 1-methyl-4-mercaptopyridine (1-m-4-MP) byAu-S bonding to electrostaticly attract negatively charged tyramine at basic condition. Differential pulse voltammetry (DPV) was employed for the detection. The limit of detection (LOD), limit of quantitation (LOQ) and linear range of tyramine was 1.17 nM, 3.94 nM and 1×10-7～5×10-9 M, respectively.[[note]]碩