A novel label-free electrochemical aptasensor for thrombin based on the {nano-Au/thionine}n multilayer films as redox probes.

摘要: Abstract Herein, a novel label-free electrochemical aptasensor based on direct immobilization of the redox probes an electrode surface was reported. Gold coated Nafion firstly modified with probe-thionine (Thi) through ion exchange adsorption. Then, help chemisorption and electrostatic adsorption, negatively charged nano-Au positively Thi were layer-by-layer (LBL) self-assembled onto surface, which formed {nano-Au/Thi + } n multilayer films for improving amount immobilizing thiolated thrombin aptamers (TBA). In presence target (TB), TBA film could catch TB resulted in barrier electro-transfer, leading to decrease current. The proposed method avoided cubsome probe labeling process, increased reduced distance between surface. Thus, approach showed high sensitivity wider linearity range from 0.12 nM 46 nM detection limit 40 pM.