Hybridization detection of enzyme-labeled DNA at electrically heated electrodes
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In this report we describe an electrochemical DNA hybridization sensor approach, in which signal amplification is achieved using heated electrodes together with an enzyme as DNA-label. On the surface of the heatable low temperature co-fired ceramic (LTCC) gold electrode, an immobilized thiolated capture probe was hybridized with a biotinylated target using alkaline phosphatase (SA-ALP) as reporter molecule. The enzyme label converted the redox-inactive substrate 1-naphthyl phosphate (NAP) into the redox-active 1-naphthol voltammetrically determined at the modified gold LTCC electrode. During the measurement only the electrode was heated leaving the bulk solution at ambient temperature. Elevated temperature during detection led to increased enzyme activity and enhanced analytical signals for DNA hybridization detection. The limit of detection at 53 °C electrode temperature was 1.2 nmol/L.
KeywordsDNA hybridization Heated biosensor Enzyme label Electrochemical detection Alkaline phosphatase
The authors are grateful to the Deutsche Forschungsgemeinschaft (DFG FL 384/4-1, FL 384/4-2 and FL 384/7-1 Heisenberg Fellowship) and the Interdisciplinary Faculty of the University of Rostock for financial support.
Supporting information is available online: Fig. S1 illustrating the calculation of the LODs from the calibration data for both 21 and 53 °C measurement temperature.