Amperometric biosensor for direct blood lactate detection

Anal Chem. 2010 Jul 1;82(13):5568-72. doi: 10.1021/ac1004426.


An amperometric sensor for lactate quantification is presented. The developed biosensor requires only 0.2 U of lactate oxidase, which is immobilized in a mucin/albumin hydrogel matrix. By protecting the platinum surface with a Nafion membrane, typical interference related to negatively charged species such as ascorbic acid has been minimized to practically undetectable levels. Electrochemical properties associated with the Nafion membrane are assessed as a function of Nafion concentration. In a phosphate buffer solution of pH 7.0, linear dependence of the catalytic current upon lactate bulk concentration was obtained between 2 and approximately 1000 microM. A detection limit of 0.8 microM can be calculated considering 3 times the standard deviation of the blank signal divided by the sensitivity of the sensor. The lactate biosensor presents remarkable operational stability and sensitivity (0.537 +/- 0.007) mA.M(-1), where the error is the standard deviation of the slope calculated from the linear regression of the calibration curve of a fresh biosensor. In this regard, the sensor keeps practically the same sensitivity for 5 months, while the linear range decreases until an upper value of 0.8 mM is reached. Assays performed with whole blood samples spiked with 100 microM lactate gave (89 +/- 6)% of recovery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albumins / chemistry
  • Biosensing Techniques / methods*
  • Electrochemical Techniques / methods*
  • Electrodes
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism
  • Hydrogels / chemistry
  • Hydrogen-Ion Concentration
  • Lactic Acid / blood*
  • Mixed Function Oxygenases / chemistry
  • Mixed Function Oxygenases / metabolism
  • Mucins / chemistry
  • Platinum / chemistry


  • Albumins
  • Enzymes, Immobilized
  • Hydrogels
  • Mucins
  • Lactic Acid
  • Platinum
  • Mixed Function Oxygenases
  • lactate 2-monooxygenase