An Efficient Graphene Quantum Dots-Based Electrochemical Cytosensor for the Sensitive Recognition of CD123 in Acute Myeloid Leukemia Cells

Leukemia stem cells (LSCs) are suitable candidates to be deployed for the diagnosis and therapy of acute myeloid leukemia (AML) patients. In this study, a novel electrochemical cytosensor was designed for the sensitive detection and quantification of KG1a cells as a model of LSCs. The developed cytosensor was based on the overexpression of cell surface protein CD123 by leukemia KG1a cells. For this purpose, the glassy carbon electrode was modified by graphene quantum dots (GQDs), Au nanoparticles, streptavidin coated AuNPs, biotinylated CD123 antibody and target cells. The dense loading of CD123 antibody and electrical enhancement on the modified electrode were carried out using GQDs, this resulting in a sensitive detection of CD123 positive cells within KG1a cells. Step by step preparation of the nanomaterial-based cytosensor and its optimization steps were confirmed by different electrochemical techniques. The field emission scanning electron microscopy (FE-SEM) images also confirmed the proper attachment of the materials and the cells on the surface of the modified electrode. The linear detection range (LDR) and limit of detection (LOD) of the developed electrochemical biosensor were recorded as 1 cell/mL and 1-25 cells/mL, respectively, which is remarkable. Importantly, the present findings are precise and highly selective in the presence of other leukemia cells (NB4, HL60, and U937 cells). Further, the versatility and accuracy of the proposed cytosensor were evaluated using clinical samples. We believe that the cytosensor proposed in this study has the potential to serve as a next generation sensor for the early detection of leukemia stem cells.