Gold Nanowires Array-Based Closed Bipolar Nanoelectrode System for Electrochemiluminescence Detection of α-Fetoprotein on Cell Surface

Abstract

Inspired by the promising applications of a closed bipolar electrodes (c-BPEs) system in electrochemiluminescence (ECL) detection of cell adhesion and disease-related biomarkers, here, a gold nanowires array-based c-BPEs system was constructed for cell surface protein detection. Regular and uniform gold nanowires array were prepared by intermittent potentiostatic deposition. Then, two poly-(dimethylsiloxane) (PDMS) chips with a hole diameter of 2 mm as a reservoir were placed at both sides of Au nanowires array to construct c-BPEs system. Thioninefunctionalized silicon dioxide nanoparticles conjugated to antibody (Ab2-Th@SiO 2 ) were used as the electrochemical probe, while [Ru(bpy) 3 ] 2+ -wrapped SiO 2 nanoparticles (Ru(II)@SiO 2 ) were employed as the ECL signal readout. Taking αfetoprotein (AFP) as model, the gold nanowires array-based c-BPEs system allowed sensitive detection of AFP at a linear range from 0.002 to 50.0 ng/mL and at least 6 living cells ascribing to the synergetic amplification effect at both sensing and reporting chambers. Besides, the amount of AFP expressed by HepG2 cells was calculated to be 6.71 pg/cell. The presented strategy with high sensitivity provided a promising and universal platform for the detection of other cancer cells and disease-related biomarkers (such as proteins, glycan, miRNA).

An electrochemiluminescence immunosensor based on multipath signal catalytic amplification integrated in a Cu2+–PEI–Pt/AuNC nanocomposite

“…To further verify the advantage of this proposed ECL immunosensor, the performance contrast compared to the previous methods for AFP detection is listed in Table 1, and the contrast results showed an obvious performance improvement of this proposed ECL immunosensor. 17–26…”

In Situ Imaging of Endogenous Hydrogen Peroxide Efflux from Living Cells via Bipolar Gold Nanoelectrode Array and Electrochemiluminescence Technology

“…The gold nanorod array was fabricated according to a previous report with slight modifications (Scheme S1). ,, Briefly, the available anodic aluminum oxide (AAO) membrane was used as a template, which was mounted on a specific holder to serve as the working electrode. Before the electrodeposition, a silver thin conducting film (thickness: ∼1 μm) was evaporated on one side of the AAO membrane by the E-beam vapor deposition method (Kurt J. Lesker).…”

Gold Microbeads Enabled Proximity Electrochemiluminescence for Highly Sensitive and Size-Encoded Multiplex Immunoassays

“…In the former case, molecular and nanomaterial luminophores that differ in redox potentials or emission wavelengths have been developed, − while the multiplexing capacity is currently limited. ECL microscopy has been employed in the study of reaction mechanisms , and the visualization of single micro-/nano-entities − and single cells. − In combination with ECL imaging technology, the spatially resolved planar array can theoretically measure as many analytes as we wished. − Moreover, the spatial resolution of these arrays can be further improved by using sub-micrometer wells or gold nanoelectrodes. − However, it is required to spare precious sample materials with macroscopical spot arrays. The microbead array is another alternative because any one of the optically addressable microbeads can function as independent signal reporters, as long as the microbeads for different targets can be spatially resolved in a single reaction volume …”