Electrogenerated Chemiluminescence Immunoassays on Nanoelectrode Ensembles Platform with Magnetic Microbeads for the Determination of Carbohydrate Antigen

Abstract

This work reports a gold nanoelectrode ensembles (Au-NEE) platform taken as a disposable electrogenerated chemiluminescence (ECL) platform with immunomagnetic microbeads for ECL immunoassays for the first time. The peak-shaped voltammograms were obtained at the Au-NEE, attributed to the total diffusional overlap. The ECL intensity at Au-NEE was 12.9 folds in the Ru(bpy) 3 2+ -tri-n-propylamine (TPA) ECL system and 19.6 folds in the luminol-H 2 O 2 system, compared with that at the Au macroelectrode using the normalized active area of the electrodes, mainly attributed to the diffusion overlap of the Au-NEE and the edge effect of the individual gold nanodisks of the Au-NEE. The ECL immunoassay on the Au-NEE platform with magnetic microbeads for the determination of cancer biomarkers was developed. Carbohydrate antigen 19-9 (CA 19-9) was chosen as a model analyte while CA 19-9 antibody on the magnetic microbeads was taken as the capture probe, and ruthenium complex-labeled CA 19-9 antibody was used as the signal probe. A "sandwich" bioconjugates on the magnetic beads were transferred onto the ECL platform, and then the ECL measurements were performed in TPA solution. The developed method showed that the ECL peak intensity was directly in proportion to the concentration of CA 19-9 in the range from 0.5 to 20 U/mL with a limit of detection of 0.4 U/mL. This work demonstrates that the Au-NEE can be employed as a useful disposable ECL platform with the merits of cheapness, low nonspecific adsorption and practical application. The proposed approach will open a new avenue in the point-of-care test for the determination of protein biomarkers.

Ultra-fast Redox Pulse for Stable Electrochemiluminescence on AuNP-Based Biosensors and Mechanism Investigation

“…Among them, the oxidation of AuNPs was assumed to be responsible for this. As displayed in Figure S15, ECL signals of Ru­(bpy) 3 2+ /TPrA on Au were weaker than that on the GCE, which is in line with reports of Gai et al It may be attributed to the resonance energy transfer between Ru­(bpy) 3 2+ and AuNPs and oxidation of AuNPs . Au was reported to form chemisorbed incipient oxides, Au–O, at 0.6–0.7 V, and Au 2 O 3 was generated exclusively at potentials >1.13 V versus Ag/AgCl .…”

“…As displayed in Figure S15, ECL signals of Ru(bpy) 3 2+ /TPrA on Au were weaker than that on the GCE, which is in line with reports of Gai et al 17 It may be attributed to the resonance energy transfer between Ru(bpy) 3 2+ and AuNPs 18 and oxidation of AuNPs. 19 Au was reported to form chemisorbed incipient oxides, Au−O, at 0.6−0.7 V, 20 and Au 2 O 3 was generated exclusively at potentials >1.13 V versus Ag/AgCl. 21 Also, AuCl 2 generated with Cl − leaked from the reference electrode, according to eq 1, 22 was also expected to involve in the redox reactions.…”

Signal Amplification Strategy Using Atomically Gold-Supported VO2 Nanobelts as a Co-reaction Accelerator for Ultrasensitive Electrochemiluminescent Sensor Construction Based on the Resonance Energy Transfer Platform

“…Electrochemiluminescence (ECL) is a process of light emission by means of a high-energy electron transfer reaction, which combines the superiorities of both chemiluminescence techniques and electrochemical methods. , Moreover, ECL does not require excitation light sources and theoretically without any background interference compared with fluorescence . Therefore, ECL has attracted extensive attention from researchers and developed as a powerful analytical technique for immunoassays, environmental monitoring, food safety, and other fields owing to simplified optical equipment, high sensitivity, and facile controllability. − …”

Highly Efficient Electrogenerated Chemiluminescence Quenching on Lipid-Coated Multifunctional Magnetic Nanoparticles for the Determination of Proteases

“…Electrogenerated chemiluminescence (ECL) biosensing methods based on functional magnetic micro-beads (MBs) with a ruthenium complex (Ru­(bpy) 3 2+ ) as the signal reagent have been widely applied in clinical diagnosis for DNA and protein biomarkers since they are extremely sensitive at subpicomolar concentrations and have an extremely wide dynamic range and easy application coupled with an automated ECL analyzer. , However, most of reported ECL biosensing methods using MBs for the determination of proteins are on the basis of the immunoassay of antigen (target) binding with the antibody. − Regarding the determination of proteases, there are usually two strategies, which can be mainly classified into a binding-based immunoassay and bio-cleavage-based bioassay. , In the immunoassay, the antibody as the recognition element is required. However, the antibody is obtained from the immunized animals and has difference between the batches.…”