Dichroic Mirror-Assisted Electrochemiluminescent Assay for Simultaneously Detecting Wild-type and Mutant p53 with Photomultiplier Tubes

The electrochemical-dependent and unstable intensity of electrochemiluminescence (ECL) makes it difficult to identify ECL in a waveband-resolved way on photomultiplier tube (PMT)-based traditional ECL analyzers. Herein, a dual-color ECL strategy is proposed by transferring ECL to two PMTs in a waveband-resolved way via dichroic mirror, simultaneously detecting wild-type p53 (WTp53) in near-infrared wavebands with CdTe (lambda(max) = 782 nm) nanocrystals as tag and mutant p53 (MUp53) in eye-visible wavebands with CdSe (lambda max = 554 nm) nanocrystals as tag. The two targets can be color-selectively determined from 10 fM to 100 pM with a limit of detection at 5 fM for MUp53 and from 50 fM to 100 pM with a limit of detection at 10 fM for WTp53, respectively. The dichroic mirror-involved ECL setup is easy to assemble for popularization, which would not only eventually enable PMT-based multiple-color ECL analysis but also make it is possible to directly determine the changed level of tumor suppressors for cancer diagnosis and therapeutic evaluation via one-pot ECL assay.