Characterization of a Wireless Potentiostat for Integration With a Novel Implantable Biotransducer

Abstract

Wireless potentiostats are being developed and commercialized for use in the development of implantable electrochemical biosensors for the monitoring of physiological markers in a wide range of pathologies. The merits and drawbacks of the Pinnacle 8151 dual potentiostat were investigated for use with a novel implantable biotransducer, the dual responsive microdisc electrode array (MDEA 5037) of ABTECH Scientific. The potentiostat was evaluated with R and RC dummy cells and with MDEA transducers modified with polypyrrolepoly(2-hydroxyethyl methacrylate) electroconductive hydrogels that were all qualified by calibrated ac impedance spectroscopy. In a laboratory setting, the 8151 potentiostat maintained a steady and unbroken signal as far away as 75 ft (23 m), and when unobstructed, up to 100 ft (30 m). The error between the two channels was determined to be 6.4 (±0.3)% and 0.7 (±0.1)% for resistor-capacitor dummy cells (RC = nominally 10 M and 1 μF) and resistor dummy cells (R = nominally 10 M ), respectively. The intra-channel variability was judged to be too large for exacting analyte determinations.

Full Fabrication and Packaging of an Implantable Multi-Panel Device for Monitoring of Metabolites in Small Animals

“…However the comparison with our system is not so straightforward, because some works focus on different applications [9], [10], some works do not target any specific applications [11], [12], other works present measurements of a single metabolite [13], or have batteries [14].…”

Biofabrication Using Pyrrole Electropolymerization for the Immobilization of Glucose Oxidase and Lactate Oxidase on Implanted Microfabricated Biotransducers

“…The fabrication of multi-analyte biotransducers is a major technical challenge when the length scales of the individual transducer elements are on the order of microns [1][2][3]. Such biotransducers are critical for in vivo (intramuscular) wireless biosensor systems [4] that allow for immediate and continual pre-hospital monitoring of lactate and glucose to inform patient specific interventions that will improve survivability from hemorrhage [2,4].…”

“…Such biotransducers are critical for in vivo (intramuscular) wireless biosensor systems [4] that allow for immediate and continual pre-hospital monitoring of lactate and glucose to inform patient specific interventions that will improve survivability from hemorrhage [2,4]. Continued examination of interstitial compartments using biosensors will aid in understanding the temporal relationships among biomarkers of stress in these environments and how they relate to hemorrhagic shock states [5].…”

“…Biotransducers fabricated with electroconductive hydrogels (ECHs) [35,36] offer the tremendous benefits of enzyme stability and protection from proteases in the host environment during in vivo application [35] but with a drawback of suboptimal sensitivity and compromised limits of detection for a wireless biosensor system [2,35]. It is believed that enzyme loading (Units/cm 2 ) and transport limitations compromise performance.…”

“…The in vivo performance of a biosensor system [37], based on the MDEA 5037 fabricated with electropolymerized polypyrrole, was examined in a Sprague-Dawley animal model. Previous characterizations of these systems in vitro have been performed and performance parameters of sensitivity, apparent Michaelis-Menten constant, limits of detection, stability, biosensor channel crosstalk, and linear range have been examined [2,27,35,38]. Sensors fabricated with polypyrrole-based electroconductive hydrogels have shown no loss of sensitivity in vitro over an 18-day period when stored in PBS buffer at 4 °C [38].…”