State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
Biosensors (Basel). 2023 Dec 10;13(12):1023. doi: 10.3390/bios13121023.
Glutamate, a non-essential amino acid produced by fermentation, plays a significant role in disease diagnosis and food safety. It is important to enable the real-time monitoring of glutamate concentration for human health and nutrition. Due to the challenges in directly performing electrochemical oxidation-reduction reactions of glutamate, this study leverages the synergistic effect of glutamate dehydrogenase (GLDH) and nanoporous gold (NPG) to achieve the indirect and accurate detection of glutamate within the range of 50 to 700 μM by measuring the generated quantity of NADH during the enzymatic reaction. The proposed biosensor demonstrates remarkable performance characteristics, including a detection sensitivity of 1.95 μA mM and a limit of detection (LOD) of 6.82 μM. The anti-interference tests indicate an average recognition error ranging from -3.85% to +2.60%, spiked sample recovery rates between 95% and 105%, and a relative standard deviation (RSD) of less than 4.97% for three replicate experiments. Therefore, the GLDH-NPG/GCE biosensor presented in this work exhibits excellent accuracy and repeatability, providing a novel alternative for rapid glutamate detection. This research contributes significantly to enhancing the precise monitoring of glutamate concentration, thereby offering more effective guidance and control for human health and nutrition.
谷氨酸是一种由发酵产生的非必需氨基酸，在疾病诊断和食品安全中发挥着重要作用。实现谷氨酸浓度的实时监测对人类健康和营养至关重要。由于直接进行谷氨酸的电化学氧化还原反应具有挑战性，本研究利用谷氨酸脱氢酶（GLDH）和纳米多孔金（NPG）的协同效应，通过测量酶反应过程中生成的 NADH 的量，实现了 50 至 700 μM 范围内谷氨酸的间接和准确检测。所提出的生物传感器具有显著的性能特征，包括 1.95 μA mM 的检测灵敏度和 6.82 μM 的检测限（LOD）。抗干扰测试表明，平均识别误差范围在-3.85%至+2.60%之间，加标样品回收率在 95%至 105%之间，三个重复实验的相对标准偏差（RSD）小于 4.97%。因此，本工作中提出的 GLDH-NPG/GCE 生物传感器具有出色的准确性和重复性，为快速检测谷氨酸提供了一种新的选择。这项研究对增强谷氨酸浓度的精确监测具有重要意义，从而为人类健康和营养提供更有效的指导和控制。
