DNA-mediated assembly of carbon nanotubes for enhancing electrochemiluminescence and its application

摘要

Graphical abstractDisplay OmittedHighlights•Label-free ECL DNA sensing strategy.•Target dependent assembly of CNTs for ECL enhancement.•Catalyzing electrochemical oxidation of TPrA to enhance ECL intensity.AbstractDNA adsorption and recognition are selective for carbon nanotubes (CNTs). In this work, we reported a novel method for control of electrochemiluminescence (ECL) enhancement through selective assembly of CNTs with DNA on indium tin oxide (ITO) electrode. The successful assembly of CNTs with well-preserved electrochemical conductivity was confirmed by scanning electron microscope and electrochemical impedance spectroscopy measurements. In comparison with the bare ITO electrode, the presence of CNTs catalyzes electrochemical reaction of an ECL coreactant, tri-n-propylamine, present in the solution, producing significantly enhanced ECL signal and ensuring substantial signal amplification. It is demonstrated that the efficiency of ECL enhancement is inversely correlated with the DNA recognition reaction, offering a promising ECL sensing platform for label-free and universal bioassay. The proposed strategy definitely differs from those works previously reported the introduction of CNTs for ECL enhancement, allowing the rise of ECL enhancement to be designed based on a biological recognition process. Just instead of the capture probe sequences, it is confirmed that the assembly of DNA with CNTs enables quantitative analysis of the different types of targets, including nucleic acid, Hg2+and thrombin.