Facile Fabrication of Highly Sensitive Pt-black Electrochemical Sensor for L-Glutamate Detection

L-glutamate is the most abundant neurotransmitter (NT) in the human brain and is involved in essentially all activities of the central nervous system. Variations in its availability have also been linked to neuronal disorders such as secondary mechanisms in traumatic spinal cord injury. Compared to conventional assays, electrochemical sensors have been an area of interest in NT measurement due to their favorable sensitivity as well as high temporal and spatial resolution. In this work, a highly sensitive, L-glutamate specific, amperometric electrochemical sensor was developed by cost-effective electrodeposition of nanostructured platinum black (Pt-black) on platinum substrates, which increases the active surface area for sensing. A self-referencing site was integrated in order to increase the signal-to-noise ratio (SNR). After further applying m-phenylenediamine dihydrochloride as a size exclusion layer, we demonstrated good sensitivity and selectivity for the miniaturized prototypes. These devices can be further developed for implantable biosensors for in vivo dynamic measurement and evaluation.