亚铁氰化钾铁氰化钾放大碳量子点电化学发光对谷胱甘肽的测定表现出良好的灵敏性

取1 V；80圈； 50 mV s-1。
GCE/poly(C-dots/A2）
C-dots
制备GCE/Poly(C-dots/A2)-Fe(CN)63-/4-
浸入含有10 mM K3Fe(CN)6/K4Fe(CN)6 (1:1) 0.1 M PBS(pH=7.0)。-0.4-0.7V；60圈；50mV s-1
文献汇报
研究背景：
谷胱甘肽（GSH）是重要的内源性抗氧化剂，用于防御毒素。不正常的含量，减缓小 孩的生长、头发脱落、器官损伤，甚至糖尿病、心血管疾病等。因此谷胱甘肽（GSH） 的检测至关重要。
碳量子点（C-dots）的优点：电化学发光，生物兼容性。 碳量子点（C-dots）的缺点：狭窄的电势窗口，减弱ECL信号。 (11-pyrrolyl-1-ylundecyl) triethylammonium tetrafluoroborate (A2)作为阳离子表面活性剂 通过静电作用与C-dots结合在一起。 亚铁氰化钾和铁氰化钾优点：作为电子注入和空穴注入，能在电化学反应中加快电子 的转移。亚铁氰化钾和铁氰化钾在poly(C-dots/A2)能增强ECL信号。
Figure 4. (A) ECL (a) and PL (b) spectrum of the poly(C-dots/A2)-Fe(CN)63−/4− system. (B) The effect of different coreactants on the ECL intensity of poly(C-dots/A2)-Fe(CN)63−/4−: (a) O2, (b) H2O2, (c) cysteine, and (d) K2S2O8. Inset: amplification of lines a, b, and c. (C) ECL response of poly(C-dots/A2), poly(C-dots/A2)-K4Fe(CN)6, poly(C-dots/A2)-K3Fe(CN)6, and poly(C-dots/A2)Fe(CN)63−/4− in Tris-HCl buffer solution (0.05 M, pH=7.4) with K2S2O8 (10 mM) and poly(C-dots/A2)-Fe(CN)63−/4− in Tris-HCl buffer solution (0.05 M, pH=7.4) with K2S2O8 (10 mM) saturated by nitrogen.
GCE/poly(C-dots/A2）
GCE/poly(C-dots/A)-Fe(CN)63-/4-
电化学研究：
Figure 1. (A) CVs of GCE obtained in 0.1 M PBS (pH =7.0) containing 10 mM K4Fe(CN)6/K3Fe(CN)6 (a) and poly(C-dots/A2)Fe(CN)63−/4− in 0.1 M PBS (pH=7.0) (b) at a scan rate of 50 mV s−1,respectively. (B) CVs of poly(C-dots/A2)-Fe(CN)63−/4− in 0.1 M PBS (pH=7.0) at various scan rates. The scan rate from inner to outer is 50 (a), 100 (b), 200 (c), 300 (d), 400 (e), and 500 mV s−1 (f). Inset: Plots of anodic and cathodic peak currents vs scan rates. (C) ECLpotential curves of poly(C-dots/A2)-Fe(CN)63−/4− in 0.05 M Tirs-HCl (pH=7.4) without (a) and with (b) 10 mM K2S2O8 at a scan rate of 100 mV s−1. (D) ECL responses of poly(C-dots/A2)-Fe(CN)63−/4−obtained during a continuous potential scan between −1.75 and 0 V.
结论：
GCE/poly(C-dots/A2）-Fe(CN)63-/4-对谷胱甘肽(GSH)的检测表现出良 好的选择性和灵敏度。
创新点：
发现了一种化学发光的途径：让Fe(CN)63-/4-参与反应使S2O82-变成 SO4.-，形成大量的C-dot＊。
实验部分：
制备C-dots
2.673 g 丙氨酸溶解在 30.0 ml 超纯水 再加入500 μL 乙二胺
转入聚四氟乙烯高压 釜中 200℃加热6 h
冷却至室温，得到 透明黑褐色液体
45℃下旋转蒸发，得到 粉末固体
在透析包（1000 MWCO） 中透析24 h
C-Dots固定在玻碳电极上：
A2通过声波降解法分散到二次蒸 馏水中制得浓度为8 mM 声波降解10 min C-dots/A2
Figure 5. CVs of the modified electrodes recorded in 0.1 M PBS (pH=7.0) for (A) GCE/poly(C-dots/A2) in the absence (a) and presence of O2 (b), (B) GCE/poly(C-dots/A2)-Fe(CN)63−/4− in the absence (a) and presence of O2 (b), (C) under N2, GCE/poly(C-dots/A2)Fe(CN)63−/4− in the absence (a) and presence of 10 mM K2S2O8 (b), (D) under ambient atmosphere, GCE/poly(Cdots/A2) Fe(CN)63−/4−in the absence (a) and presence of 10 mM K2S2O8 (b).
Figure 3. SEM (A,C,D) and TEM (B) images for (A) polyA2, (B) Cdots, (C) poly(C-dots/A2), and (D) poly(C-dots/A2) Fe(CN)63−/4−. Inset shows the photographs of C-dots/A2 solution under visible light (left) and under 365 nm UV light (right).
Figure 2. (A) ECL-time curves of poly(C-dots/A2)-Fe(CN)63−/4− in the presence of (a−j) 0, 0.1, 0.3, 0.5, 0.7, 1, 2, 4, 7, and 10 μM GSH. The electrolyte is Tris-HCl (0.05 M, pH=7.4) with 10 mM K2S2O8 and 0.1 M KCl. (B) The corresponding ECL vs GSH concentration curves. Inset: Linear calibration plot for GSH detection. (C) The ECL response of poly(C-dots/A2)-Fe(CN)63−/4− in the presence of interfering substances.