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Interference of glucose sensing by amino acids
1Surgical Research Laboratory, Montefiore University Hospital, Pittsburgh, Pennsylvania.
ASAIO Journal (American Society for Artificial Internal Organs : 1992)
|January 1, 1994
Summary
Amino acids interfere with glucose sensing electrodes. Phenylalanine and cystine caused greater signal reduction than alanine or lysine, but glucose sensing remains feasible in their presence.
Area of Science:
- Electrochemistry
- Biosensing
- Analytical Chemistry
Background:
- Nonspecific electrodes in glucose sensing face interference from membrane-permeable substances.
- Understanding amino acid interference is crucial for accurate glucose measurement.
Purpose of the Study:
- To investigate the interference effects of various amino acids on glucose sensing using a nonspecific electrode.
- To quantify the impact of alanine, lysine, phenylalanine, and cystine on glucose signal reduction.
Main Methods:
- Cyclic voltammetry was employed using a platinum (Pt) electrode.
- The reductive current of glucose was measured at -0.750 V versus Ag/AgCl.
- Experiments were conducted in Krebs-Ringer phosphate buffer (pH 7.4) at 37°C with increasing amino acid concentrations.
Main Results:
- All tested amino acids (alanine, lysine, phenylalanine, cystine) exhibited an inhibitory effect on the glucose signal.
- Phenylalanine and cystine demonstrated more pronounced interference than alanine and lysine.
- Significant signal reduction occurred at low concentrations (<2.0 mg/dl for alanine/lysine, <0.5 mg/dl for phenylalanine/cystine), with further increases having minimal additional effect.
Conclusions:
- Amino acids significantly interfere with glucose detection by nonspecific electrodes.
- The study confirms the feasibility of glucose sensing in biological fluids containing interfering amino acids.
- Differential interference levels among amino acids provide insights for sensor development and signal correction strategies.