Template Free Anisotropically Grown Gold Nanocluster Based Electrochemical Immunosensor for Ultralow Detection of Cardiac Troponin I

Abstract

Anisotropic gold nanostructures have fascinated with their exceptional electronic properties, henceforth exploited for the fabrication of electrochemical sensors. However, their synthesis approaches are tedious and often require a growth template. Modern lifestyle has caused an upsurge in the risk of heart attack and requires urgent medical attention. Cardiac troponin I can serve as a biomarker in identification of suspected myocardial infection (heart attack). Hence the present work demonstrates the fabrication of a sensing platform developed by assimilating anisotropic gold nanoclusters (AuNCs) with anti cTnI antibody (acTnI) for the detection of cardiac troponin I (cTnI). The uniqueness and ease of synthesis by a template-free approach provides an extra edge for the fabrication of AuNC coated electrodes. The template-free growth of anisotropic AuNCs onto the indium tin oxide (ITO) glass substrates offers high sensitivity (2.2 × 10⁻⁴ A ng⁻¹ mL cm⁻²) to the developed sensor. The immunosensor was validated by spiking different concentrations of cTnI in artificial serum with negligible interference under optimized conditions. The sensor shows a wide range of detection from 0.06–100 ng/mL with an ultralow detection limit. Thus, it suggests that the template-free immunosensor can potentially be used to screen the traces of cTnI present in blood serum samples, and the AuNCs based platform holds great promise as a transduction matrix, hence it can be exploited for broader sensing applications.