Electrochemical DNA detection using Hoechst dyes in microfluidic chips

We fabricate microfluidic DNA sensors based on the electrochemical method that uses Hoechst 33258 [2′-(4-hydroxyphenyl)-5-(4-methyl-1-piperazinyl)-2,5′-bi(1H-benzimidazole)] as a DNA intercalator. These chips are fabricated without a probe immobilization process, thereby being more simply regenerated than other typical DNA chips. Linear sweep voltammetric measurements show an anodic-current decrease consistent with the DNA duplex formation which occurs when the target is fully complementary to the probe, enabling sequence-specific DNA detection.

► Immobilization-free DNA sensors are fabricated in microfluidic platforms.
► Hoechst 33258 is used as an electrochemical DNA intercalator.
► The anodic current is lowest when the target DNA is complementary to the probe.
► These chips are more easily regenerated than other typical DNA chips.