Hybridization detection of enzyme-labeled DNA at electrically heated electrodes

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.