The interference of HEPES buffer during amperometric detection of ATP in clinical applications |
| |
Authors: | Jean-Francois Masson Estelle Gauda Boris Mizaikoff Christine Kranz |
| |
Institution: | (1) School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA 30332-0400, USA;(2) Division of Neonatology Research Laboratories, Johns Hopkins Hospital, 600 N. Wolfe St., Baltimore, MD 21287-3200, USA;(3) Present address: Département de chimie, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, QC, Canada, H3C 3J7 |
| |
Abstract: | HEPES-based biological buffer is subject to photooxidation upon exposure to fluorescent illumination. Thereby hydrogen peroxide
is generated, which interferes with amperometric oxidoreductase-based biosensors for glucose or adenosine triphosphate (ATP).
These biosensors operate at an oxidation potential above 500 mV vs. the standard calomel electrode (SCE) and involve hydrogen
peroxide as the electroactive molecule detected at the electrode surface. False-positive detection of ATP was observed in
HEPES buffer utilizing an amperometric microbiosensor based on the co-immobilization of glucose oxidase and hexokinase for
detection of ATP in biological specimens. Electrochemical, mass spectrometric, 31P NMR, and 1H NMR studies indicate that complexation of ATP and HEPES induced by the presence of Ca2+ in HEPES buffer decreases the photooxidation of HEPES. Consequently, the hydrogen peroxide background concentration is reduced,
thereby leading to erroneous ATP detection at the dual-enzyme microbiosensor, which determines an increase in ATP via a reduced
hydrogen peroxide signal. |
| |
Keywords: | 4-(2-Hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) Phototoxicity ATP microbiosensor Hexokinase Glucose oxidase Ringer’ s solution |
本文献已被 PubMed SpringerLink 等数据库收录! |
|