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

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Cardiovascular disease (CVD) remains a leading global cause of mortality.
• Developing sensitive biosensors for CVD markers is crucial for early diagnosis and treatment.
• Cardiac Troponin I (cTnI) is a critical biomarker for acute myocardial infarction (AMI).

Purpose of the Study:

• To develop an electrochemical biosensor for sensitive and early detection of cardiac Troponin I (cTnI).
• To utilize acetic acid functionalized graphene quantum dots (fGQDs) as an interface for cTnI detection.
• To investigate the diagnostic capacity of the developed biosensor for acute myocardial infarction.

Main Methods:

• Electrochemical detection using cyclic voltammetry (CV) and amperometry.
• Functionalization of graphene quantum dots with acetic acid (fGQDs).
• Carbodiimide conjugation for immobilizing cTnI onto the fGQDs.
• Fourier Transform Infrared Spectrometry (FTIR) for confirming the sensing mechanism.

Main Results:

• The fGQDs modified Au electrode demonstrated sensitive electrocatalytic oxidation of cTnI.
• Achieved a linear detection range of 0.17 to 3 ng/mL for cTnI.
• Obtained a low limit of detection of 0.02 ng/mL for cTnI.
• Bland-Altman plots indicated bias between intra-/inter-cTnI assays and calibrated assays.

Conclusions:

• The developed fGQDs-based electrochemical biosensor offers a promising method for cTnI detection.
• This innovative approach shows potential for the early diagnosis of acute myocardial infarction.
• Further validation with clinical samples is required to confirm applicability in healthcare settings.