Application of Au cage/Ru(bpy)32+ nanostructures for the electrochemiluminescence detection of K562 cancer cells based on aptamer

• Au nanocage was prepared to load more Ru(bpy)32+ for signal amplification. Hollow micro-/nanostructures have attracted great attention over the past few decades due to their unique properties, such as designable morphology, void space, low density, low coefficients of thermal expansion and refractive indexes, which are attributed to the special construction and composition.
• Aptamers a have many advantages over antibodies, such as low molecular weight, easy but reproducible production and low cost.
• Pt-CNTs was prepared as biointerface for the immobilization of cancer cells due to their good biological compatibility, excellent conductivity and large surface area.
• This new cyto-sensor may be quite promising, with potential broad applications in cancer early diagnosis due to the excellent analytical performance.

In this work, an electrochemiluminescence (ECL) cytosensor for ultrasensitive and selective cytosensing of K562 cancer cells was developed. Pt nanoparticles (PtNPs) dotted carbon nanotubes (CNTs) was immobilized on the working electrode which can not only improve the electronic transmission rate but also increase the surface area. And aptamers modified electrode was employed for specific and efficient cancer cell capture. A new class of nanoprobes were also prepared by integrating the functions of specific recognition of concanavalin A (Con A) and signal amplification of Au cage/Ru(bpy)32+ nanostructures. With a sandwich-type cytosensor format, the amount of Au cage/Ru(bpy)32+-labeled Con A increased with the increment of K562 cancer cells in the samples, resulting in the increase of ECL signals. The as-proposed cytosensor exhibited excellent analytical performance toward the cytosensing of K562 cells in a wide detection linear range from 500 to 5.0 × 106 cells mL−1 with a detection limit of 500 cells mL−1. Moreover, the proposed method showed good precision, acceptable stability and reproducibility.

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