A mediator-free, non-enzymatic electrochemical biosensor was constructed by covalent immobilization of a genetically engineered periplasmic glutamate binding protein onto gold nanoparticle-modified, screen-printed carbon electrodes (GluBP/AuNP/SPCE) for the purpose of direct measurement of glutamate levels. Glutamate serves as the predominant excitatory neurotransmitter in the central nervous system. As high levels of glutamate are an indicator of many neurologic disorders, there is a need for advancements in glutamate detection technologies. The biosensor was evaluated for glutamate detection by cyclic voltammetry. Binding of glutamate to the immobilized glutamate binding protein results in a conformational change of the latter that alters the microenvironment on the surface of the sensor, which is manifested as a change in signal. Dose–response plots correlating the electrochemical signal to glutamate concentration revealed a detection limit of 0.15 μM with a linear range of 0.1-0.8 μM. Selectivity studies confirmed a strong preferential response of the biosensor for glutamate against common interfering compounds.

通过将基因工程周质谷氨酸结合蛋白共价固定到金纳米粒子修饰的丝网印刷碳电极 (GluBP/AuNP/SPCE) 上，构建了一种无介质、非酶电化学生物传感器，用于直接测量谷氨酸水平. 谷氨酸是中枢神经系统中主要的兴奋性神经递质。由于高水平的谷氨酸盐是许多神经系统疾病的指标，因此需要改进谷氨酸盐检测技术。通过循环伏安法评估生物传感器的谷氨酸检测。谷氨酸与固定化谷氨酸结合蛋白的结合导致后者的构象变化，从而改变传感器表面的微环境，表现为信号的变化。将电化学信号与谷氨酸浓度相关联的剂量-响应图显示检测限为 0.15 μM，线性范围为 0.1-0.8 μM。选择性研究证实了谷氨酸生物传感器对常见干扰化合物的强烈优先响应。