Polydopamine-gold composite-based electrochemical biosensor using dual-amplification strategy for detecting pancreatic cancer-associated microRNA.

Herein, we developed a dual-amplification-boosted, translational electrochemical biosensor for the detection of pancreatic cancer-associated microRNA, miR-196b. A biosensing event occurred when a hairpin target probe recognized miR-196b as a result of the opening of an electrode hairpin probe on a polydopmine-gold (PDA-Au) composite-modified screen-printed carbon electrode. The PDA-Au composite was synthesized in a alkaline condition where dopamine polymerized into polydopamine while gold(III) ion was in-situ reduced to gold nanoparticle, characterized by FT-IR, SEM, cyclic voltammetry and gel electrophoresis.