Electroanalysis on an Interdigitated Electrode for High-Affinity Cardiac Troponin I Biomarker Detection by Aptamer–Gold Conjugates

Abstract

The primary reasons for myocardial infarction (MI) are pericarditis, arrhythmia, and heart failure, causing predominant deaths worldwide. Patients need a potential diagnostic system and treatment before cardiomyocyte damage. Cardiac biomarkers are released from myocytes immediately after a heart attack. Troponin is an efficient biomarker released from dead cells within a few hours. Aptamers are artificial antibodies used effectively in the biosensor field for biomarker detection. Along with aptamers, the application of nanomaterials is also expected to enhance the detection limits of biosensors. In this investigation, selected aptamers against cardiac troponin I (cTnI) were conjugated with gold nanoparticles (GNPs) to diagnose MI and compared with an aptamer-only control group on an interdigitated electrode surface. Based on electroanalysis, cTnI was detected at concentrations as low as 1 fM, and the detection limit improved to 100 aM when the aptamer was conjugated with GNP. In addition, aptamer–GNP conjugates increased the current level at the tested concentrations of cTnI. Control experiments with noncomplementary aptamers and relevant proteins did not result in notable changes in the current, demonstrating the selective detection of cTnI.

“On the Detection of cTnI - A Comparison of Surface-Plasmon Optical -, Electrochemical -, and Electronic Sensing Concepts”

“…The simple question: what is the molecular mechanism and/or a theoretical model by which one could understand that the sensor response changes by a factor of 3-5 (!) upon varying the cTnI concentration by 5-7 orders of magnitude [28][29][30][31][32] (Calling this "linear" is another story…). All reports refer to a bimolecular reaction between the ligand, cTnI, and its antibody or specific aptamer.…”

Nanotechnology for cardiovascular diseases

“… 33 Nanomaterials with excellent optoelectronic properties greatly improve the detection sensitivity by orders of magnitude. 21 , 34 , 35 , 36 , 37 , 38 With ZnSnO 3 perovskite nanomaterial-decorated glassy carbon electrodes, Singh et al. designed a label-free EC biosensor to detect TnT.…”

Sensitive silica‐alumina modified capacitive non‐Faradaic glucose sensor for gestational diabetes

“…Surface chemical functionalization is one of the crucial parts to immobilize the probe (GOx) at higher numbers. [29][30][31] Herein, the coupling of APTES and Glu has played a major role in enhancing the number of GOx attachment and demonstrated the high performance.…”

“…To overcome the current issues, this study shows that the non‐Faradaic capacitive glucose sensor has several advantages for high‐performance such as optimized finger and gap regions, right surface chemical, cheaper, easier to use, higher sensitivity, selectivity, and to be operated by both alternate and direct currents. Surface chemical functionalization is one of the crucial parts to immobilize the probe (GOx) at higher numbers 29–31 . Herein, the coupling of APTES and Glu has played a major role in enhancing the number of GOx attachment and demonstrated the high performance.…”