1 research outputs found
Dual Electrochemiluminescence Signal System for <i>In Situ</i> and Simultaneous Evaluation of Multiple Cell-Surface Receptors
A mutiplex
cytosensor based on a dual electrochemiluminescence (ECL) signal system
was fabricated for <i>in situ</i> and simultaneous detection
of the expression levels of multiple cell-surface receptors, mannose
and epidermal growth factor receptor (EGFR), using luminol-capped
gold nanoparticles (Au@luminol) and CdS quantum dots (CdS QDs) as
potential-resolved ECL nanoprobes. Two spatially resolved areas on
indium tin oxide (ITO) electrodes were modified with polyaniline (PANI)
by electropolymerization, on which gold nanoparticles (AuNPs) were
attached to strengthen conductivity and stability of the sensing interface.
Human mucin1 protein (MUC1) aptamer was immobilized onto AuNPs for
capturing MUC1-positive MCF-7 cells. Au@luminol and CdS QDs as ECL
nanoprobes were covalently linked with concanavalin A (ConA) and epidermal
growth factor (EGF) to label MCF-7 cells on the two areas of the cytosensor
separately. Compared to conventional multiplex biosensor, we demonstrated
a novel analysis platform for the simultaneous detection of multiple
cell-surface receptors; it could provide two sensitive and potential-resolved
ECL signals during one potential scanning and avoid cross-reactivity
between the two nanoprobes. The quantification of MCF-7 cells on the
two spatially resolved areas could be achieved over the linear range
from 10<sup>2</sup> to 1.0 × 10<sup>6</sup> cells mL<sup>–1</sup> with a detection limit of 20 cells mL<sup>–1</sup>. This
multiplex cytosensor was further applied for simultaneous quantitative
evaluation of the expression levels of mannose and EGFR on MCF-7 cells,
revealed that the average numbers of mannose and EGFR per captured
MCF-7 cell were 1.2 × 10<sup>6</sup> and 0.86 × 10<sup>5</sup> with the relative standard deviation of 5.3% and 4.2%, respectively.
The multiplex cytosensor was capable of evaluating multiple cell-surface
receptors, which would be beneficial to developing a better diagnostic
tool for diseases