| 摘要 |
Improved low-potential electrochemical sensors and method for rapid, accurate, in vitro and in vivo measurement of the concentration of carbohydrates in organic or biological fluids by cyclic voltammetric or coulometric scan within a restricted voltage domain and identifying one or more oxidation and/or reduction current peaks, with the concentration of the carbohydrate being a linear function of the current output. Two well defined, sharp, distinctly separated, specific, reproducable and interference-free peaks have been discovered in the low-potential voltage domain of -0.9V to -0.2V, cathodic reduction Peak 1 and anodic oxidation Peak 2 in the range of -0.70V to -0.90V. The scan is pulsed or a steady sweep, and sensitivity increases with increased scan rate in the range of 30-50 mV/sec. Pulses may range on the order of 20-50 millisecond in duration, and sampling during the last 1.5 milliseconds of the pulse restricts values to pure oxidation/reduction currents. Cyclic and/or pulsed scanning regenerates the electrodes making the sensor drift free. A system is disclosed employing the sensor as part of an implantable insulin pump which is microprocessor controlled, thus functioning as an artificial pancreas. The sensors can also be used in bedside monitoring systems as an indwelling sensor introduced by catheterization, for in-line extracorporeal shunt systems, or for non-invasive measurement of carbohydrate levels.
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