Electrochemical Immunosensor for Cardiac Troponin I Detection Based on Covalent Organic Framework and Enzyme-Catalyzed Signal Amplification

Abstract

Herein, a highly sensitive electrochemical immunosensor was presented for the cardiac troponin I (cTnI) determination using a multifunctional covalent organic framework-based nanocomposite (HRP-Ab2-Au-COF) as the signal amplification probe. The spherical COF with a large surface area was synthesized in a short time by a simple solution-based method at room temperature. The good biocompatibility, low toxicity, and high stability in water of the COF guarantee its application in biosensing. Besides, its high porosity makes it an excellent carrier for loading abundant horseradish peroxidase (HRP). The modified gold nanoparticles on the surface of COF not only provide a load platform for secondary antibody (Ab2) but also improve the conductivity of COF. Under the synergistic effect of the hydrogen peroxide (H 2 O 2 ) and HRP, hydroquinone (HQ) in the solution is catalytically oxidized to benzoquinone (BQ), which is then reduced on the electrode surface to generate the electrochemical signal. The designed probes not only show the specific recognition behavior of Ab2 to cTnI but also improve the sensitivity of the biosensing system due to the signal amplification caused by the excellent enzyme catalytic performance of HRP. Based on the H 2 O 2 -HRP-HQ signal amplification system, the biosensor for cTnI was fabricated and exhibited a linear response as a function of logarithmic cTnI concentration ranging from 5 pg/mL to 10 ng/mL, and the detection limit was 1.7 pg/mL. Moreover, the biosensor exhibited excellent recovery and reproducibility in the actual sample testing. This work provided a simple approach to determine cTnI quantitatively in practical samples and broadened the utilization scope of the COF-based nanocomposite in the electrochemical immunosensor.

Tunable Competitive Absorption-Induced Signal-On Photoelectrochemical Immunoassay for Cardiac Troponin I Based on Z-Scheme Metal–Organic Framework Heterojunctions

“…Evidence from the scientific literature has revealed that cardiac biomarkers, e.g., myoglobin, B-type natriuretic peptide, heart-type fatty acid binding protein (h-FABP), and cardiac troponin I (cTnI), can provide a rapid diagnosis of AMI. − However, detection of the extremely small variations in the concentrations of these biomarkers during the onset of AMI remains challenging, which limits accurate diagnosis. Several techniques have been proposed for the analysis of AMI biomarkers including fluorescence, , chemiluminescence, photothermal biosensing, , and electrochemical detection. − Among these, advanced photoelectrochemical (PEC) bioanalysis enables the fusion of photodriven electrochemical responses with various biological recognition events to monitor physiological and pathological parameters, making it a promising and burgeoning technique in life science research. − Currently, developing unique signal-on sensing mechanisms is a significant research branch in PEC bioanalysis due to their reduced background signals and high sensitivity. Therefore, the development of a signal-on amplified PEC bioanalysis for AMI biomarker detection is highly desirable.…”

Surface-Enhanced Carboxyphenyl Diazonium Functionalized Screen-Printed Carbon Electrode for the Screening of Tuberculosis in Sputum Samples

“…While there is nothing new about the technique, the performance of the HRP-H 2 O 2 -HQ technique is undeniable. Many studies have proven that the technique is reliable and can improve biosensor sensitivity due to the signal amplification by the excellent enzyme catalytic reaction of HRP [ 20 , 21 , 22 ]. A remarkable electrochemical reduction signal of benzoquinone is generated from the HRP catalyzation towards the reaction between H 2 O 2 and HQ.…”

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

“…Furthermore, when horseradish peroxidase was incorporated as a signal amplifier, Au-modified DMTP-TAPB-COF was used to construct an enzymatic electroimmunosensor for cardiac troponin I. 771 The response current of this sensor was linearly related to the logarithmic concentration of cardiac troponin I with a wide sensitivity range from 5 pg mL −1 to 10 ng mL −1 and a low detection limit of 1.7 pg mL −1 . Glucose oxidase, hemoglobin, horseradish peroxidase, immunoglobulin G and cardiac troponin T did not interfere with the sensor, which could detect cardiac troponin I specifically in serum samples.…”