Highly Selective and Stable Microdisc Biosensors for L-Glutamate Monitoring


Glutamate mediates most of the excitatory synaptic transmission in the brain, and its abnormal regulation is considered a key factor underlying the appearance and progression of many neurodegenerative and psychiatric diseases. In this work, a microdisc-based amperometric biosensor for glutamate detection with highly enhanced selectivity and good stability is proposed. The biosensor utilizes the enzyme glutamate oxidase which was dip-coated onto 125 μm diameter platinum discs. To improve selectivity, phosphatidylethanolamine was pre-coated prior to enzyme deposition, and electropolymerization of o-phenylenediamine was performed to entrap the enzyme within a polymer matrix. A variety of coating configurations were tested in order to optimize biosensor performance. For stability measurements, biosensors were biased continuously and calibration curves calculated each day for a period of 5–6 days. The optimized biosensors exhibited very high sensitivity (71 ± 1 mA M−1 cm−2), low detection limit of ∼2.5 μM glutamate, selectivity (over 87% against ascorbic acid), very good temporal stability during continuous use, and a response time of <5 s. These biosensors are therefore good candidates for further development as devices for continuous monitoring during traumatic brain injury or neurosurgery.


The Publisher's final version can be found by following the DOI link.


Biosensors, Glutamate, electropolymerisation


Govindarajan, S., McNeil, C.J., Lowry, J.P., McMahon, C.P., O’Neill, R.D. (2013) Highly Selective and Stable Microdisc Biosensors for L-Glutamate Monitoring. Sensors & Actuators B: Chemical,178, pp.606–614.


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