Electrochemical Determination of L‐Lactate Using Phenylboronic Acid Monolayer‐Modified Electrodes

Abstract

AbstractThe surface of a gold (Au) disk electrode was modified with a self‐assembled monomolecular layer of dithiobis(4‐butylamino‐m‐phenylboronic acid) (DTBA‐PBA) to prepare L‐lactate‐sensitive electrodes. The DTBA‐PBA‐modified electrodes exhibited an attenuated cyclic voltammogram (CV) for the Fe(CN)63− ion in the presence of L‐lactate, as a result of the formation of phenylboronate ester of L‐lactate accompanied with the addition of OH− ion to the boron atom. In other words, the negatively charged DTBA‐PBA monolayer blocked the electrode surface from the access of the Fe(CN)63−/4− ions. Thus, the DTBA‐PBA monolayer‐modified Au electrode can be used for determining L‐lactate on the basis of the change in redox current of Fe(CN)63−/4− ions. The calibration graph useful for determining 1–30 mM L‐lactate was obtained.