Electrochemiluminescent sensor for the detection of DNA hybridization using stem-loop structure DNA as capture probes

摘要

An electrochemiluminescent (ECL) sensor is presented for the detection of DNA hybridization using single-strand DNA with stem-loop structure as capture probes. After the probe DNA was immobilized on an gold electrode, labeled with ruthenium complex, and formed a stem-loop structure, this sensor produced a high ECL signal. On hybridization with the complementary target DNA, the ECL intensity significantly decreased. Different from other DNA sensors, in which the probe DNA was labeled in advance with a signalling molecule and then assembled onto an electrode, the approach presented here relies on assembling first, and then labelling with ruthenium complex, without the complicated purifying processes after the probe DNA was labeled. The ECL intensity versus the concentration of the target DNA was linear in the range from 1.0 pM to 0.1 μM with a detection limit of 0.5 pM. The biosensor conceivably can be used as a general approach for the ECL detection of DNA.