Department of Pharmaceutical Chemistry, College of Pharmacy, Najran University, Najran, Saudi Arabia.
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt.
Anal Chim Acta. 2023 Sep 1;1272:341498. doi: 10.1016/j.aca.2023.341498. Epub 2023 Jun 8.
A novel molecularly imprinted ratiometric-based sensor was designed for highly selective and ultrasensitive electrochemical detection of glutathione (GSH). The sensor consists of porous carbon co-doped with nitrogen and sulfur formed on the surface of graphite electrode (N, S@PC/GE). Silver nanoparticles (Ag) were grown on the surface of N, S@PC/GE to improve the conductivity/surface area of the sensor and represent an internal reference signal for ratiometric response. The monomer (pyrrole-4-carboxylic acid, Py-COOH) was electro-polymerized on the surface of Ag/N, S@PC/GE in the presence of Cu (II) to form Cu-MIP@Ag/N, S@PC/GE. Addition of GSH decreased the signal of Ag at 0.18 V (oxidation of Ag) due to coordination complexation, while the signal response at 0.83 V (oxidation of Ag-GSH complex) was increased. Under optimum conditions, the ratio response (I/I) was increased with increasing the concentration of GSH in the range of 0.01-500 nM with a detection limit (S/N = 3) of 0.003 nM. The electrochemical sensor exhibits many advantages including low LOD, high selectivity, good reproducibility, and satisfactory stability. The sensor was successfully applied to determine GSH in dietary supplements and human serum samples with recoveries % ranged from 97.4 to 101.8% and relative standard deviation % (RSD %) did not exceed 3.8%. This research paper introduces new information for the construction of molecular imprinted ratiometric-based electrochemical sensors for highly selective and sensitive detection of (bio) molecules.
一种新型的基于分子印迹的比率型传感器被设计用于对谷胱甘肽（GSH）进行高选择性和超灵敏的电化学检测。该传感器由在石墨电极表面形成的共掺杂氮和硫的多孔碳（N，S@PC/GE）组成。在 N，S@PC/GE 表面生长了银纳米粒子（Ag），以提高传感器的导电性/表面积，并代表比率响应的内部参考信号。在 Ag/N，S@PC/GE 表面，在 Cu（II）存在下，单体（吡咯-4-羧酸，Py-COOH）被电化学聚合以形成 Cu-MIP@Ag/N，S@PC/GE。由于配位络合作用，加入 GSH 会降低 0.18 V 处的 Ag 信号（Ag 的氧化），而 0.83 V 处的信号响应（Ag-GSH 络合物的氧化）则会增加。在最佳条件下，随着 GSH 浓度在 0.01-500 nM 范围内的增加，比率响应（I/I）增加，检测限（S/N = 3）为 0.003 nM。该电化学传感器具有许多优点，包括低检测限、高选择性、良好的重现性和令人满意的稳定性。该传感器成功应用于测定膳食补充剂和人血清样品中的 GSH，回收率%在 97.4%至 101.8%之间，相对标准偏差%（RSD%）不超过 3.8%。本研究论文为构建高选择性和灵敏的（生物）分子比率型电化学传感器提供了新信息。
