Novel peptidylated surfaces for interference-free electrochemical detection of cardiac troponin I

Abstract

Novel peptidylated surfaces were designed to minimise interferences when electrochemically detecting cardiac troponin I in complex biological samples. Disulfide-cored peptide dendrons featuring carbomethoxy groups were self-assembled on gold electrodes. The carbomethoxy groups were deprotected to obtain carboxylic groups used to immobilise antibodies for cardiac troponin I marker. The chemisorption of two types of peptides, one containing triazole and the other with native peptide bonds, on a gold substrate was studied by quartz crystal microbalance (QCM), surface plasmon resonance (SPR) and X-ray photoelectron spectroscopy (XPS). Peptides formed ordered self-assembled monolayers, contributing to a more efficient display of the subsequently immobilised antibodies towards their binding to the antigen. As a result, electrochemical immunosensors prepared by self-assembly of peptides afforded higher sensitivities for cardiac troponin I than those prepared by the chemisorption of alkane thiolated compounds. Triazolic peptide-modified immunosensors showed extraordinary sensitivity towards cardiac troponin I [1.7µA/(ng/mL) in phosphate buffer], but suffered from surface fouling in 10% serum. Modification with non-triazolic peptides gave rise to anti-fouling properties and still enabled the detection of cardiac troponin I at pg/mL concentrations in 10% serum without significant matrix effects.

Point-of-Care Compatibility of Ultra-Sensitive Detection Techniques for the Cardiac Biomarker Troponin I—Challenges and Potential Value

“…Several immobilisation approaches have been proposed to assist in mitigating the negative effects of these interfering molecules, some of which incorporate the use of self-assembled monolayers (SAMs), hydrogels and zwitterionic compounds among others [79,80,81,82,83]. Dhawan et al have designed peptidylated surfaces to minimise biological fouling during cTnI detection [84]. This work incorporated the evaluation of triazolic and non-triazolic peptides to determine the most effective anti-fouling immobilisation surface.…”

Fabrication of Non‐enzymatic Electrochemical Glucose Sensor Based on Pd−Mn Alloy Nanoparticles Supported on Reduced Graphene Oxide

“…To fabricate the efficient electrochemical sensor, the selection of appropriate electrode material is very important to control its performance . Generally, nanostructured materials are promising candidates in the field of diagnosis and medical treatment .…”

“…Generally, nanostructured materials are promising candidates in the field of diagnosis and medical treatment . In view of literature, the noble metals nano‐architectures have been approved as promising tools to design the non‐enzymatic electrochemical sensors owing to their excellent features including abundant electro‐active sites, fast electron transport ability, good stability and higher electrochemical efficacy . To date, numerous tailor‐made noble metals and metal oxide nanostructures such as Au , Ag , Pt , Ru , Rh , and Pd have been reported to show excellent electro‐catalytic sensing properties toward glucose and other analytes.…”

Peptide-based antifouling aptasensor for cardiac troponin I detection by surface plasmon resonance applied in medium sized Myocardial Infarction

“…Guo, et al described a rapid and sensitive method for detecting cTnI, which was based on the changes of longitudinal SPR wavelength of gold nanorods upon antibody-antigen binding [23]. However, applications in complex media should be taken into consideration since biofouling caused by nonspeci ic adsorption will seriously in luence the reliability and accuracy of the biosensor in clinical sample analysis [24,25]. Therefore, a bifunctional biosensor with anti-fouling characteristics as well as high speci ic binding to cTnI is needed.…”