Amperometric Detection of Dopamine in Vivo with an Enzyme Based Carbon Fiber Microbiosensor

Abstract

We developed a novel implantable enzyme-based carbon fiber biosensor for in vivo monitoring of dopamine. The biosensor is fabricated using tyrosinase immobilized in a biocompatible matrix consisting of a biopolymer, chitosan and ceria-based metal oxides, deposited onto the surface of a carbon fiber microelectrode with a diameter of approximately 100 microm. Tyrosinase catalyzes the conversion of dopamine to o-dopaquinone, and the reduction of o-dopaquinone, which requires a low potential difference, was detected electrochemically. The role of each component in the sensing layer was systematically investigated in relation to the analytical performance of the biosensor. In its optimal configuration, the biosensor demonstrated a detection limit of 1 nM dopamine, a linear range of 5 orders of magnitude between 10 nM and 220 microM, a sensitivity of 14.2 nA x microM(-1), and good selectivity against ascorbic acid, uric acid, serotonin, norepinephrine, epinephrine, and 3,4-dihydroxy-l-phenylalanine (L-DOPA). The system provided continuous, real time monitoring of electrically stimulated dopamine release in the brain of an anesthetized rat. Levels of dopamine up to 1.69 microM were measured. This new implantable dopamine biosensor provides an alternative to fast scan cyclic voltammetry for in vivo monitoring of dopamine.

Microelectrode Arrays Modified with Nafion/Nanoporous AuPt Nanoparticles for in vivo Detection of Dopamine

“…Therefore, it was believed that the increased responsive currents and slow decline of peak currents upon nomifensine administration were mainly due to the accumulation of DA concentration in fluids outside of cells, which is consistent with previous reports. (2,7,37) In a word, the above results indicated that amperometry coupled with Nafion/AuPt-alloy-nanoparticle-modified Au sites possessed sufficient feasibility for enabling in vivo recording of DA concentration in the brain of anesthetized rats.…”

“…This factor is very important because major sources of interference, such as ascorbic acid (AA), also exist in body fluids together with DA and show very high concentrations with similar oxidization potentials to that of DA. Hence, a variety of composites, such as tyrosinase-based materials, (7) ion-exchange membranes, (8,9) conducting polymer films, (10) and molecularly imprinted polymer, (11) have been used to enhance the selectivity of DA detection. It is well known that the cation exchange polymer, Nafion, possesses the ability to repel negative ions and combine with positively charged species, because of the appearance of anionic sites in its structure.…”

A new nano-composite carbon ink for disposable dopamine biosensors

“…The current responses to the precursor of DA (L-DOPA) and DA metabolite (DOPAC) could be ascribed to their similar structure to DA and their interference were a common problem in electrochemical DA sensor systems. 35 It is apparently noted that L-DOPA and DOPAC could be interfere the sensor performance. However, their much lower sensitivities to the sensor and relatively lower concentration level in real samples 35 compared with the values of DA, could overcome this interference related limitation.…”

“…35 It is apparently noted that L-DOPA and DOPAC could be interfere the sensor performance. However, their much lower sensitivities to the sensor and relatively lower concentration level in real samples 35 compared with the values of DA, could overcome this interference related limitation.…”

Voltammetric Detection of Biological Molecules Using Chopped Carbon Fiber

“…11 An amperometric biosensor of dopamine using carbon fiber with tyrosinase has also been constructed. 12 A carbon fiber microcylinder modified with toluidine blue has been proposed to determine lactate dehydrogenase. 13 Chopped carbon fibers, which are an example of CFRPs, have been used as a reinforcing agent for thermoplastic resin.…”