金奈米粒子應用於偵測鉻離子與硫醇分子

Abstract

金奈米粒子表面修飾 PSDTC (O-phospho-L-serinedithiocarbamic acid)，可應用於偵測 Cr3 離子。Cr3+ 離子會造成金奈米粒子的聚集，PSDTCAuNPs 溶液顏色由酒紅色轉變成藍紫色；藉由 EDTA 實驗，可知該聚集過程為可逆反應。利用 PSDTCAuNPs 溶液於波長 651 nm 與 525 nm 的吸收值比值，可定量 0.2 3.4 μM Cr3+ 離子濃度，其偵測極限為4.23 nM。PSDTCAuNPs 溶液於 pH 5 10範圍內可辨識 Cr3+ 離子，並可有效用於偵測湖水樣品中的 Cr3+ 離子不受干擾。 經檸檬酸還原方法還原 HAuCl4 所得之金奈米粒子，於表面修飾 螢光化學分子 BODIPY 形成 BDPAuNPs，可用於偵測生物硫醇分子。Cysteine (Cys) 藉由硫醇官能基與金奈米粒子表面形成穩定的共價鍵結，導致 BDP 分子脫附金奈米粒子表面，伴隨螢光放射的產生。此 BDPAuNPs 對 Cys 展示優秀的辨識能力而不受其他胺基酸分子干擾。利用 BDPAuNPs 溶液位於波長 516 nm 的螢光放射強度變化量，可定量 0.4  1.4 mM Cys 濃度，偵側極限為 1.15 M。BDPAuNPs 溶液於 pH 5  12範圍內可有效辨識硫醇分子，並成功應用於偵測細胞中的硫醇分子。

O-phospho-L-serinedithiocarbamic acid (PSDTC) functionalized Au nanoparticles (PSDTCAuNPs) have been developed for selectively and sensitively detecting Cr3+. AuNPs were prepared by reducing HAuCl4 with sodium citrate and then using PSDTC as the capping agent. PSDTCAuNPs exhibits high selectivity for Cr3+ over other cations. This Cr3+ -induced aggregation of PSDTCAuNPs was monitored by the naked eye and UV-vis spectroscopy with a detection limit of 4.23 nM. PSDTCAuNPs showed good selectivity and the best detection of Cr3+ was achieved in a pH range of 5 10. In addition, PSDTCAuNPs were also used to detect Cr3+ in lake water samples, with low interference BODIPY functionalized Au nanoparticles (BDPAuNPs) have been developed for selectively detecting cysteine (Cys). Gold nanoparticles were prepared by reducing HAuCl4 with sodium citrate and then using BDP as the capping agent. BDPAuNPs exhibits high selectivity for Cys over other amino acids. This Cys-induced fluorescence turn-on process of BDPAuNPs was monitored by fluorescent spectroscopy with a detection limit of 1.15 M. BDPAuNPs showed good selectivity and the best detection of Cys was achieved in a pH range of 5 12. In addition, BDPAuNPs can be used as a fluorescent probe for detecting thiols in living cells