Paper-based electrochemiluminescence biosensor for cancer cell detection

Here a novel paper-based electrochemiluminescence (ECL) device was developed for the detection of HL-60 cancer cells. In this approach, porous filter paper as a thin-layer electrochemical cell connected to a sheet of ITO working electrode. Au nanoparticles (Au NPs) and graphene were coated on the surface of ITO to immobilize capture HS-DNA. Then, the aptamer of HL-60 cancer cells, which is labeled with Ru(bpy)32 +-conjugated silica nanoparticles (RuSi@Ru(bpy)32 +) is hybridized with the capture DNA to form bioconjugates. In the presence of HL-60 cells, the aptamer would conjugate with glycoprotein at cell surface and RuSi@Ru(bpy)32 + NP-aptamer would be released. After the dissociation of RuSi@Ru(bpy)32 + NP-aptamer from the surface of ITO, ECL signal would decline. This simple, portable and disposable testing platform could detect HL-60 cancer cells down to 56 cells/mL.