金奈米粒子應用於偵測鉛離子、碘離子和抗壞血酸

Abstract

一、 TTP修飾之金奈米粒子應用於偵測鉛離子

合成硫辛酸衍生物 (TTA) 修飾之金奈米粒用來選擇性地偵測鉛離子。 利用NaBH4 還原TP和四氯金酸，開環的TP上的硫醇基會和金奈米粒子表面產生金硫共價鍵，形成TP修飾之金奈米粒子。再和azidoacetic acid進行 click reaction，使TP的炔端和azidoacetic acid的疊氮端，產生一五圓環結構，生成TTA-AuNPs。鉛離子會和TTA上的羧基和五圓環錯合，造成TTA-AuNPs聚集，使金奈米粒子溶液顏色由酒紅色變為紫色。利用TTA-AuNPs位於700 nm的吸收值變化，可以定量0.5 ~ 8 M的鉛離子，偵測極限為16.7 nM。TTA-AuNPs適合偵測鉛離子的pH值範圍為5 ~ 10。此外，TTA-AuNPs可以應用於偵測湖水樣品中的鉛離子。

二、 ATTP 修飾之金奈米粒子應用於偵測碘離子

合成硫辛酸衍生物 (ATTP) 修飾之金奈米粒用來選擇性地偵測碘離子。 利用NaBH4 還原TP和四氯金酸，開環的TP上的硫醇基會和金奈米粒子表面產生金硫共價鍵，形成TP修飾之金奈米粒子。再和azidoacetamide進行 click reaction，使TP的炔端和azidoacetamide的疊氮端，產生一五圓環結構，生成ATTP-AuNPs。碘離子會和ATTP上的氨基錯合，造成ATTP-AuNPs聚集，使金奈米粒子溶液顏色由酒紅色變為紫色。利用ATTP位於700 nm的吸收值變化，可以定量0.5 ~ 6 M的碘離子，偵測極限為15 nM。ATTP-AuNPs適合偵測碘離子的pH值範圍為2 ~ 7。此外，ATTP-AuNPs可以應用於偵測湖水樣品中的碘離子。 三、 硫氫苯硼酸修飾之螢光金奈米團簇應用於偵測抗壞血酸

硫氫苯硼酸 (MPBA) 修飾之螢光金奈米團簇可以用來偵測抗壞血酸。利用NaBH4 還原四氯金酸，硫氫苯硼酸上的硫醇基會和金奈米粒子表面產生金硫共價鍵，形成MPBA-AuNCs。硫氫苯硼酸會和抗壞血酸上的雙醇形成硼酸酯化合物，造成MPBA-AuNCs聚集。由於量子侷限效應被破壞，使得MPBA-AuNCs的螢光被淬熄。利用MPBA-AuNCs位於312 nm的螢光強度變化，可以定量20 ~ 200 M的抗壞血酸，偵測極限為4.1 M。MPBA-AuNCs適合偵測抗壞血酸的pH值範圍為4 ~ 12。

(1) TTA Functionalized Gold Nanoparticles for Colorimetric Sensing of Pb2+ Ions New lipoic acid-based derivative functionalized gold nanoparticles (TTA-AuNPs) for sensitive and selective colorimetric detection of Pb2+ have been developed. TTA-AuNPs were prepared by reducing a mixture of HAuCl4 and TP with sodium borohydride in aqueous solvent, and forming a triazole structure between TP and azidoacetic acid through the click reaction. Aggregation of TTA-AuNPs was induced immediately in the presence of Pb2+, yielding a color change from wine-red to purple. This Pb2+-induced aggregation of TTA-AuNPs was monitored by the naked eye and UV-vis spectroscopy with a detection limit of 16.7 nM. TTA-AuNPs showed excellent selectivity toward Pb2+compared to other metal ions through the interaction between the free carboxyl group and triazole structure of TTA and Pb2+. The best detection of Pb2+ was achieved in a pH range of 5 ~ 10. Furthermore, TTA-AuNPs were applied to detect Pb2+ in lake water with low interference.

(2) ATTP Functionalized Gold Nanoparticles for Colorimetric Sensing of I- Ions New lipoic acid-based derivative functionalized gold nanoparticles (ATTP-AuNPs) for sensitive and selective colorimetric detection of I- have been developed. ATTP-AuNPs were prepared by reducing a mixture of HAuCl4 and TP with sodium borohydride in aqueous solvent, and forming a triazole structure between TP and azidoacetamide through the click reaction. Aggregation of ATTP-AuNPs was induced immediately in the presence of I-, yielding a color change from wine-red to purple. This I--induced aggregation of ATTP-AuNPs was monitored by the naked eye and UV-vis spectroscopy with a detection limit of 15 nM. ATTP-AuNPs showed excellent selectivity toward I- compared to other anions through the interaction between the amino groups of ATTP and I-. The best detection of I- was achieved in a pH range of 2 ~ 7. Furthermore, ATTP-AuNPs were applied to detect I- in lake water with low interference.

(3) MPBA Functionalized Fluorescent Gold Nanoclusters for Sensing of Ascorbic Acid 4-mercaptophenylboronic acid (MPBA) functionalized fluorescent gold nanoclusters for selective detection of ascorbic acid have been developed. MPBA-AuNCs were prepared by reducing HAuCl4 with sodium borohydride in the presence of MPBA. MPBA formed boronate ester with the diols of ascorbic acid, causing the aggregation of MPBA-AuNCs. This induced the quenching of MPBA-AuNCs fluorescence in the presence of ascorbic acid. The ascorbic acid-induced quenching of MPBA-AuNCs fluorescence was monitored by the fluorescence spectrophotometer with a detection limit of 4.1M.The best detection of ascorbic acid was achieved in a pH range of 4 ~ 12.