An electrochemical aptamer biosensor based on "gate-controlled" effect using β-cyclodextrin for ultra-sensitive detection of trace mercury.

摘要: A new strategy for construction an electrochemical biosensor Hg(2+) analysis with extremely high sensitivity was proposed based on "T-Hg(2+)-T" coordination by aptamers and "gate-controlled" amplification switch of the channels probe. SH-β-cyclodextrin self-assembled gold electrode to form orderly arranged molecularly layer interspaces among β-CDs; thionine labeled aptamer then linked assembled β-CD. When added, combined formed structure, which caused folded covered block off channel probe entrance. The oxidative current decreased, provide basis determination Hg(2+). With gate-controlled amplification, changes trace amounts will produce great current. sensor exhibited significantly higher a detection limit 5.0×10(-15) mol/L, is lower than other reported methods.