Functionalized Graphene Quantum Dot Interfaced Electrochemical Detection of Cardiac Troponin I: An Antibody Free Approach

Abstract

According to the World Health Organization (WHO), cardiovascular disease (CVD) is the leading cause of death in the world every year. The design and development of biosensors for the detection of CVD markers could be one of the major contributions of the scientific community to society. In this context, acetic acid functionalized graphene quantum dots (fGQDs) were used as an interface for the electrochemical detection of cardiac Troponin I (cTnI). The interaction of cTnI with fGQDs for the early diagnosis of acute myocardial infarction was investigated using cyclic voltammetry (CV) and amperometry. The carbodiimide conjugation between the N-H group of cTnI and the functionalized COOH group on GQDs enabled the detection of cTnI biomarker. The same sensing mechanism was confirmed using Fourier Transform Infrared Spectrometry (FTIR). The fGQDs modified Au electrode showed remarkable electrocatalytic oxidation of cTnI with good stability and sensitivity over a linear range of 0.17 to 3 ng mL−1 and a low detection limit of 0.02 ng mL−1. Bland-Altman plots substantiate a bias between the intra-/inter-cTnI assay and calibrated cTnI assay with 95% limits of agreement (mean difference ± 1.96 SD). The aim of this study is to describe an innovative method to detect cardiac biomarker cTnI and provide preliminary data on its diagnostic capacity. At the same time, its applicability in clinical setting will have to be validated with a significant number of samples collected from patients.

Applications of Graphene Quantum Dots in Biomedical Sensors

“…The immunoreaction was examined with the help of DPV and CV, attaining an LOD of 20 fg mL -1 over a wide cTnI concentration range from 10 -6 to 10 ng mL -1 . Very recently, Lakshmanakumar et al designed a model for cTnI biomarker determination [291]. In this work, acetic Figure 19.…”

“…The immunoreaction was examined with the help of DPV and CV, attaining an LOD of 20 fg mL −1 over a wide cTnI concentration range from 10 −6 to 10 ng mL −1 . Very recently, Lakshmanakumar et al designed a model for cTnI biomarker determination [291]. In this work, acetic acid functionalized GQDs (fGQDs) were used as an interface for cTnI, where the interaction between cTnI and fGQDs was investigated by CV as well as amperometry.…”

Nanoscale Technologies in Highly Sensitive Diagnosis of Cardiovascular Diseases

“…Once CK-MB was captured on the electrode, the ECL signal was determined by Tris(2,2 -bipyridyl)-ruthenium(II) chloride ([Ru(bpy) 3 ] 2+ Cl) and tri-n-propylamine (TPrA), in which Ru(bpy) 3 ] 2+ Cl was used as luminophore and TPrA was the co-reactant. Moreover, Lakshmanakumar et al (2019) functionalized graphene quantum dots with acetic acid (fGQDs) on the Au electrode to detect cTnI. The cTnI was recognized via carbodiimide conjugation between the N-H group of cTnI and the COOH group on fGQDs instead of antibody-antigen interaction.…”

“…The cTnI was recognized via carbodiimide conjugation between the N-H group of cTnI and the COOH group on fGQDs instead of antibody-antigen interaction. The interaction of cTnI and fGQDs was examined by cyclic voltammetry (CV) and amperometry (Lakshmanakumar et al, 2019). They detected cTnI over a linear range of 0.17-3 ng/mL and offered a detection limit of 0.02 ng/mL with good stability and sensitivity.…”

Sensitive impedimetric detection of troponin I with metal–organic framework composite electrode

“…Graphene, carbon nanotubes (CNTs), conducting polymers, and silicon nanowires are the recently investigated popular transducer surfaces for the development of electrochemical biosensors for cTnI. [15][16][17][18][19] As advanced functional materials, the metal-organic frameworks (MOF) have garnered great interest in recent years because of their fascinating material properties. [20][21][22][23][24] MOFs have also been suggested useful for the development of electrochemical biosensors for different categories of analytes.…”