奈米粒子應用於NAD(P)H: 醌氧化還原酶1、銀離子與鎘離子檢測

Abstract

(一) 醌修飾之摻雜錳離子硫化鋅量子點為NAD(P)H: 醌氧化還原酶1感測探針 在摻雜錳離子硫化鋅量子點(ZnS(Mn2+) QDs)表面修飾醌衍生物，使磷光淬息，得到NAD(P)H: 醌氧化還原酶1 (NQO1) 感測探針(Q-ZnS(Mn2+) QDs)。探針表面上的醌衍生物與NQO1反應，被還原成氫醌後，從探針表面離去，中止光誘導電子轉移 (photo-induced electron transfer, PET)，啟動磷光放射機制，以偵測NQO1的存在。從NQO1酵素動力學實驗結果，顯示NQO1對Q-ZnS(Mn2+) QDs有良好的反應活性，並可從磷光生成速率定量NQO1的濃度。Q-ZnS(Mn2+) QDs對於細胞有極低的生物毒性，可用於NQO1表現過量的細胞顯影實驗，並檢測出NQO1表現於細胞質與細胞核。成功發展了一個具有高選擇性與高靈敏度的NQO1感測探針，可用於偵測NQO1表現過量的人類腫瘤細胞。 (二) 腺嘌呤修飾之金奈米粒子應用於銀離子檢測 設計金奈米粒子表面修飾腺嘌呤衍生物(N-1-(2-mercaptoethyl)adenine)，做為銀離子的感測探針(MEA-AuNPs)。MEA-AuNPs對銀離子檢測有專一性，銀離子會導致MEA-AuNPs聚集，使金奈米水溶液的顏色從酒紅色轉變成藍紫色。MEA-AuNPs檢測銀離子適用於pH 6-9的水溶液，其偵測極限為 3.3 nM。從核磁共振光譜可以得知銀離子與腺嘌呤(adenine)有良好的交互作用，使得MEA-AuNPs對於銀離子檢測有優異的選擇性與高靈敏。MEA-AuNPs的銀離子檢驗，不會受到其他金屬離子的影響，可用於真實湖水中的微量銀離子檢測，得回收率為95.3-103.5% ，因此MEA-AuNPs可適用於複雜環境的微量銀離子檢測應用。 (三) 二吡咯甲硫酮修飾之金奈米粒子為高靈敏鎘離子感測探針 二吡咯甲硫酮修飾金奈米粒子(DP-AuNPs)是一個新型高靈敏度與專一性的鎘離子感測探針。在含有鎘離子的樣品中，DP-AuNPs發生聚集現象，金奈米水溶液顏色，從酒紅色轉變成藍紫色，從紫外-可見光光譜圖可知吸收峰從波長520 nm紅位移至波長 635 nm，其偵測極限達至16.6 nM。DP-AuNPs對鎘離子有專一性。DP-AuNPs對於鎘離子有很好的配位能力，不會受到其他金屬離子的影響，所以適用於複雜的水溶液樣品檢測鎘離子，其適合偵測pH範圍為4-9.5的水溶液中，可用於檢測真實湖水樣品微量鎘離子，並展現其良好檢測結果。

(1) Quinone modified Mn-Doped ZnS Quantum Dots for Room Temperature Phosphorescence sensing of NQO1 A new room-temperature phosphorescence NAD(P)H: quinone oxidoreductase isozyme 1 (NQO1) sensor was developed by using quinone-modified Mn-doped ZnS quantum dots (Q-ZnS(Mn2+) QDs). It can selectively detect NQO1 in vitro and vivo through phosphorescence generated by reduction-initiated removal of quinones on its surface with NQO1. Enzyme kinetics of NQO1 was measured by phosphorescence enhancement of Q-ZnS(Mn2+) QDs revealed its highly catalytic activity towards Q-ZnS(Mn2+) QDs. High viability of cells in presence of Q-ZnS(Mn2+) QDs showed the low cytotoxicity to A549 cells from MTT assay. Therefore, Q-ZnS(Mn2+) QDs can be applied to detect NQO1 which is overexpressed in cytoplasma and nucleus of cancer cells. We successfully developed a highly selective room-temperature phosphorescent probe to detect the human cancer cells with the overexpressed NQO1 (2) Highly selective and sensitive colorimetric detection of Ag(I) using N-1-(2-mercaptoethyl)adenine functionalized gold nanoparticles A sensitive and selective colorimetric Ag+ detection method was developed by using N-1-(2-mercaptoethyl)adenine functionalized gold nanoparticles (MEA-AuNPs). The presence of Ag+ immediately induced aggregation of MEA-AuNPs, yielding a color change from wine-red to purple. This Ag+-induced aggregation of MEA-AuNPs was monitored by bare eye and UV-vis spectroscopy with a detection limit of 3.3 nM. MEA-AuNPs showed excellent selectivity toward Ag+ compared with other metal ions through interaction between adenine and Ag+. The best detection of Ag+ was achieved at pH 6-9. Furthermore, MEA-AuNPs were applied to detect Ag+ in lake water with low interference. (3) Colorimetric detection of Cd(II) ions based on di(1H-pyrrol-2-yl)methanethione functionalized gold nanoparticles A sensitive and selective colorimetric Cd2+ detection method was developed using di(1H-pyrrol-2-yl)methanethione functionalized gold nanoparticles (DP-AuNPs). Aggregation of DP-AuNPs was induced immediately in the presence of Cd2+, yielding a color change from wine-red to purple. This Cd2+-induced aggregation of DP-AuNPs was monitored using the naked eye and UV-Vis spectroscopy with a detection limit of 16.6 nM. The DP-AuNPs showed excellent selectivity toward Cd2+ compared to other metal ions through the interaction between di(1H-pyrrol-2-yl)methanethione and Cd2+. Optimal detection of Cd2+ was achieved over a pH range from 4 to 9.5. Furthermore, DP-AuNPs were applied to detect Cd2+ in lake water, showing low interference.