Facility Agriculture: Intelligent SensorsDepartment of Mechanical Engineering / Wu, Chia-Che / Associate Professor  
設施農業:智慧感測【機械工程學系/吳嘉哲副教授】

論文篇名 英文:Voltammetric measurement of Escherichia coli concentration through p-APG hydrolysis by endogenous beta-galactosidase
中文:利用電化學伏安檢測技術與半乳糖苷酶水解作用檢測水中大腸桿菌濃度
期刊名稱 MICROCHEMICAL JOURNAL
發表年份,卷數,起迄頁數 2020154, 104641
作者 Fan, Yu-Jui; Hsu, Yu-Chen; Gu, Bing-Chen; Wu, Chia-Che(吳嘉哲)*
DOI 10.1016/j.microc.2020.104641
中文摘要 本論文提出了一個快速檢測水中大腸桿菌的方法,利用大腸桿菌內源酶半乳糖苷酶(β-gal)水解乳糖(p-APG)的能力和十二烷基硫酸鈉(SDS)可以讓大腸桿菌細胞壁透化,已加速乳糖(p-APG)水解反應。最後利用伏安法測定乳酸的濃度,進而反推大腸桿菌的濃度。本研究成功測得自來水、中興湖和康橋旱溪溪水水中的大腸桿菌濃度。檢測範圍為102–104大腸桿菌聚落,整體檢測時間少於100分鐘。利用本論文提出的檢測方法可以降低繁瑣的檢測程序,增加使用者操作的便利性,未來可以成功發展出現地檢測的水中大腸桿菌濃度檢測器。另外,本計畫不需要昂貴與笨重的儀器設備,可以發展成可攜式檢測裝置。
英文摘要 This paper reports a facile electrochemical detection method for Escherichia coli (E. coli) that does not use DNA amplification or immunoassay. The detection principle is based on the activity of the β-galactosidase (β-gal) endogenous enzyme, which hydrolyzes p-aminophenyl-β-D-galactopyranoside (p-APG) into p-aminophenol. After E. coli consumes p-APG within 30 min, the remaining p-APG is oxidized on a gold electrode using cyclic voltammetry and square wave voltammetry. The β-gal expression level is increased through treatment with a β-gal expression inducer (isopropyl-β-D-thiogalactopyranoside), and the hydrolysis reaction of p-APG is facilitated through permeabilization treatment with sodium dodecyl sulfate. The calibration curve for E. coli has a working range of 102–10colony-forming units per mL in nutrient broth buffer. The total assay time is less than 100 min. The successful application of this approach indicates the possibility of rapid detection.


Figure: Schematic of the experiments. E. coli was sequentially added IPTG, SDS, and p-APG, and the p-APG concentration, which is related to E. coli concentration, was determined by using voltammetry