A Label-free Cardiac Troponin T Electrochemiluminescence Immunosensor Enhanced by Graphene Nanoplatelets

Abstract

In this study, a direct and label-free immunosensor was designed and constructed by modifying the screen-printed electrode with graphene nanoplatelets (GNPs) for the detection of the cardiac troponin T (cTnT). Firstly, GNPs were drop-casted onto carbon working electrode. Monoclonal cTnT antibodies were then immobilized on the GNPs via physical adsorption; finally, BSA was introduced to block non-specific binding sites. The detection of cTnT was performed using an electrochemiluminescence (ECL) technique with tris(bipyridine)ruthenium(II) chloride ([Ru(bpy)3]Cl2) used as a luminophore and TPrA (tripropylamine) as a co-reactant. The ECL intensity was demonstrated to be directly proportional to the cTnT concentration where a linear range from 100 pg mL-1 to 5 fg mL-1 of the cTnT detection was established. An extremely low limit of detection was achieved to be 0.05 fg mL-1 with an outstanding specificity. Additionally, this immunosensor showed excellent percentage recovery for real samples analyses in artificially spiked human serum.

Recent advancement in sensitive detection of carcinoembryonic antigen using nanomaterials based immunosensors

“…These integrated receptor-transducer devices allow quantitative or semiquantitative analytical information about actual biological samples [28,47]. They are generally divided into bio-catalytic sensors [37,49] and bio-affinity sensors [50,51].…”