Electrochemiluminescent biosensor for ultrasensitive detection of lymphoma at the early stage using CD20 markers as B cell-specific antigens

Herein, by taking advantage of the special binding of an aptamer to the membrane surface of a B cell and accumulation of the positive charges of a nanocomposite, including luminol-chitosan-platinum nanoparticles (L-Cs-Pt NPs), on the negatively charge of the aptamer phosphate backbone, a sensitive, simple, selective and rapid strategy for the detection of lymphoma cells by a new label-free electrogenerated chemiluminescence (ECL) aptasensor has been introduced. With increasing concentrations of B lymphoma cells, the nanocomposite detaches from the aptamer, leading to a decrease in the ECL of a luminol and H2O2 system. With high loading of luminol and Pt NPs on a chitosan, together with the electrocatalytic effect of Pt NPs, enhanced sensitive detection of cancer cells with a limit of detection of 31 cells/mL was achieved. Step-by-step modification and biosensor response to cancer cells was monitored by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and ECL. The aptasensor exhibited excellent specificity for lymphoma cells vs breast cancer (MCF-7) and human embryonic kidney (HEK293) cell lines as potential interferents. Finally, the performance of the aptasensor in blood samples was assessed against a commercial flow cytometric method. Satisfactory results confirmed the applicability of the proposed biosensing platform. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

In this study, a novel label-free electrogenerated chemiluminescence (ECL) aptasensor was developed for the sensitive detection of lymphoma cells by utilizing the special binding of an aptamer to the membrane surface of B cells and the accumulation of a nanocomposite on the aptamer phosphate backbone. The enhanced sensitive detection of cancer cells was achieved with a limit of detection of 31 cells/mL, and the aptasensor exhibited excellent specificity for lymphoma cells compared to other cell lines. The performance of the biosensing platform was confirmed through satisfactory results obtained from blood samples when compared to a commercial flow cytometric method.