Sensitive Immunosensor for N‑Terminal Pro-brain Natriuretic Peptide Based on N‑(Aminobutyl)-N-(ethylisoluminol)-Functionalized Gold Nanodots/Multiwalled Carbon Nanotube Electrochemiluminescence Nanointerface

A novel electrochemiluminescence (ECL) immunosensor was developed for the determination of N-terminal pro-brain natriuretic peptide (NT-proBNP) by using N-(aminobutyl)-N-(ethylisoluminol) (ABEI)-functionalized gold nanodots/chitosan/multiwalled carbon nanotubes (ABEI/GNDs/chitosan/COOH-MWCNTs) hybrid as nanointerface. First, ABEI/GNDs/chitosan/COOH-MWCNTs hybrid nanomaterials were grafted onto the surface of ITO electrode via the film-forming property of hybrid nanomaterials. The anti-NT-proBNP antibody was connected to the surface of modified electrode by virtue of amide reaction via glutaraldehyde. The obtained sensing platform showed strong and stable ECL signal. When NT-proBNP was captured by its antibody immobilized on the sensing platform via immunoreaction, the ECL intensity decreased. Direct ECL signal changes were used for the determination of NT-proBNP. The present ECL immunosensor demonstrated a quite wide linear range of 0.01–100 pg/mL. The achieved low detection limit of 3.86 fg/mL was about 3 orders of magnitude lower than that obtained with electrochemistry method reported previously. Because of the simple and fast analysis, high sensitivity and selectivity, and stable and reliable response, the present immunosensor has been successfully applied to quantify NT-proBNP in practical plasma samples. The success of the sensor in this work also confirms that ABEI/GNDs/chitosan/COOH-MWCNTs hybrid is an ideal nanointerface to fabricate a sensing platform. Furthermore, the proposed strategy could be applied in the detection of other clinically important biomarkers

Additional file 1: Figure S1. of In Vitro Effects of Hollow Gold Nanoshells on Human Aortic Endothelial Cells

A representative profile of size distributions of the hollow gold nanoshells in suspension. (DOCX 42 kb

Three-Biomarker Joint Strategy for Early and Accurate Diagnosis of Acute Myocardial Infarction via a Multiplex Electrochemiluminescence Immunoarray Coupled with Robust Machine Learning

Acute myocardial infarction (AMI) represents a leading cause of death globally. Key to AMI recovery is timely diagnosis and initiation of treatment, ideally within 3 h of symptom onset. Cardiac troponin T (cTnT) is the gold standard yet a low cTnT result cannot rule out AMI at early times. Here, we develop a three-biomarker joint strategy for early and accurate diagnosis of AMI via an electrochemiluminescence (ECL) immunoarray coupled with robust machine learning. The ECL immunoarray is based on an array microchip with a single-electrode and chemiluminescent immuno-Gold (ciGold) nanoassemblies. The ciGold immunoarray was obtained by successively assembling nanocomposites of Cu2+/cysteine complexes and N-(aminobutyl)-N-(ethylisoluminol) bifunctionalized gold nanoparticles combined with chitosan and antibody conjugated gold nanoparticles on the surface of a microchip. Three biomarkers, including cardiac troponin I, heart type fatty acid binding protein, and copeptin, were simultaneously detected in 260 serum samples from patients presenting with chest pain by an innovative multiplexed ECL immunoarray, and classified via the three-biomarker joint assessment model using support vector machines. The model achieved perfect discrimination (100% sensitivity and specificity) for AMI vs non-AMI patients, substantially higher than cTnT alone. Within 12 h of symptom onset, high-sensitivity cardiac troponin T (hs-cTnT) misclassified >20% of patients, while the joint biomarker assessment model retained perfect accuracy. As the time between symptom onset and testing became shorter, the degree to which the joint assessment model outperformed hs-cTnT increased. The proposed three-biomarker joint strategy is obviously superior to hs-cTnT for early and accurate diagnosis of AMI, hopefully reducing AMI mortality and saving limited medical resources