The effect of temperature on electrochemically driven denaturation monitored by SERS

• Electrochemically driven melting experiments of DNA between 10 and 28 °C were carried out.
• Two different 21 and 22-base long double stranded DNA sequences were used.
• Increasing the temperature results to less negative melting potentials, up to ~ 18 °C.
• These values are temperature independent in the region 18–28 °C.
• Reducing the experimental temperature improves the sensitivity of the biosensor.

Scanning the electrochemical potential negative results in the gradual denaturation of dsDNA immobilised at a nanostructure gold electrode, the DNA melting is monitored by SERS. We demonstrate the effect of the experimental temperature on the electrochemically driven melting (E-melting) by carrying out experiments between 10 and 28 °C using two DNA duplexes (20 and 21 base pairs). Significant temperature dependence for both the melting potentials, Em, and the steepness of the melting curves was found over the range 10 to 18 °C. Above 18 °C the results were found to be independent of temperature. The relative temperature insensitivity of the melting potentials above 18 °C is advantageous for the application of the electrochemically driven melting technique because precise temperature control is not necessary for measurements that are carried out around room temperature. Conversely temperature dependence below 18 °C offers a way to improve discrimination for highly similar DNA sequences.

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