Electrochemical Detection of NT-proBNP Using a Metalloimmunoassay on a Paper Electrode Platform

Abstract

In this paper, we demonstrate an electrochemical method for detection of the heart failure biomarker, N-terminal prohormone brain natriuretic peptide (NT-proBNP). The approach is based on a paper electrode assembly and a metalloimmunoassay; it is intended for eventual integration into a home-use sensor. Sensing of NT-proBNP relies on the formation of a sandwich immunoassay and electrochemical quantification of silver nanoparticle (AgNP) labels attached to the detection antibodies (Abs). There are four important outcomes reported in this article. First, compared to physisorption of the detection Abs on the AgNP labels, a 27-fold increase in signal is observed when a heterobifunctional cross-linker is used to facilitate this labeling. Second, the assay is selective in that it does not cross-react with other cardiac natriuretic peptides. Third, the assay forms in undiluted human serum (though the electrochemical analysis is carried out in buffer). Finally, and most important, the assay is able to detect NT-proBNP at concentrations between 0.58 and 2.33 nM. This performance approaches the critical NT-proBNP concentration threshold often used by physicians for risk stratification purposes: ~0.116 nM.

Redox Polyelectrolyte Modified Gold Nanoparticles Enhance the Detection of Adenosine in an Electrochemical Split‐Aptamer Assay

“…In our assay, the redox polyelectrolyte surrounded the nanoparticle provides a label that immediately can generate a signal, in contrast to previous electrochemical sandwich immunoassay involving metallonanoparticles, where the signal is generated after several steps involving first a chemical dissolution step, with the introduction of new reagents, followed by an electrochemical step to complete the determination . Therefore, the combination of two dynamics areas of materials science (nanotechnology and soft matter) can improve the detection limit of a recognition assay by generating the equivalent to a macromolecule constituted by a scaffold with multiple binding sites and multiple signal‐generating moieties.…”

“…A second labeled antibody subsequently binds to the analyte for the signal generation. Colloidal metal labels have been widely used in the last two decades in this type of assay . A similar approach can be taken with the adenosine aptamer, whose original hairpin sequence can be cut in the loop domain (Scheme A, left) .…”

“…Electrochemical detection is a very convenient method since it can be used in turbid samples, a relevant issue in many clinical and biological studies, and due to its hardware simplicity, a low cost per assay can be easily achieved. The use of colloidal metal labels in sandwich assays allows a sensitive response; however, most of the examples presented in the literature involve the nanoparticle‘s chemical dissolution, involving the addition of reagents and introducing more steps to the detection process or complicated construction schemes …”

Aptamers for Detection and Diagnostics (ADD) is a proposed mobile app acquiring optical data from conjugated quantum nanodots to identify molecules indicating presence of SARS-CoV-2 virus: Why public health and healthcare need smartphone sensors as a platform for early detection and prevention

“…Decades after the discovery of atrial natriuretic peptide 310 (ANP, 1981), brain or B-type natriuretic peptide 311 (BNP, 1987) and C-type natriuretic peptide 312 (CNP, 1990), we still do not have SENSIBLE monitoring for BNP even though BNP sensors 313 including an aptamer-based 314 sensor for BNP-32 and cardiac Troponin I are available. These and other 315 biomarkers (CRP5/CRP6, TNFα) are indicators of cardiovascular dysfunction including congestive heart failure (CHF) and state of the patient after myocardial infarction, in addition to other conditions.…”

Aptamers for Detection and Diagnostics (ADD) is a proposed mobile app acquiring optical data from conjugated quantum nanodots to identify molecules indicating presence of SARS-CoV-2 virus: Why public health and healthcare need smartphone sensors as a platform for early detection and prevention

“…Decades after the discovery of atrial natriuretic peptide 312 (ANP, 1981), brain or B-type natriuretic peptide 313 (BNP, 1987) and C-type natriuretic peptide 314 (CNP, 1990), we still do not have SENSIBLE monitoring for BNP even though BNP sensors 315 including an aptamer-based 316 sensor for BNP-32 and cardiac Troponin I are available. These and other 317 biomarkers (CRP5/CRP6, TNFα) are indicators of cardiovascular dysfunction including congestive heart failure (CHF) and state of the patient after myocardial infarction, in addition to other conditions.…”