Versatile “on–off” biosensing of thrombin and miRNA based on Ag(i) ion-enhanced or Ag nanocluster-quenched electrochemiluminescence coupled with hybridization chain reaction amplification

Abstract

A novel biosensing platform based on the Ag(I) ion-enhanced or Ag nanocluster (NC)-quenched electrochemiluminescence (ECL) of CdSe quantum dots (QDs) was designed for versatile “on–off” assays of thrombin (TB) and miRNA, in which bipedal molecular machine (BMM)-triggered surface programmatic chain reaction (SPCR) coupled with mesoporous silica nanoparticle (MSN) multiple amplification is used to introduce plentiful QDs and Ag⁺ ions to significantly improve the ECL signal.