Ultra-sensitive facile CdS nanocrystals-based electrochemical biosensor to detect myocardial infarction marker troponin

Abstract

Here, we report on a reproducible one-pot synthesis of high-quality and monodispersed CdS semiconducting nanocrystals (NCs) by mixing precursors cadmium acetate and elemental sulfur into the new solvent system of dibenzyl ether and oleylamine without using any extra reagent or precursor activator. The NCs (5 nm) exhibited a dominant band-edge emission with a good photoluminescence quantum yield of 13.76% without trap emission. The CdS NCs were characterized using UV–Vis and photoluminescence spectroscopy, electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The practical efficiency of the synthesized NCs was proved by applying the synthesized CdS NCs as the tracer in the engineering of an immunosandwich biosensor to evaluate the cardiac troponin (cTn) marker for the diagnosis and monitoring of myocardial infarction (MI). The biosensor revealed significant analytical efficiency with the limit of detection of 2 ng L−1 and the linear dynamic range of 5–1000 ng L−1, which is lower than the existing cutoff values (13–20 ng L−1). Having capitalized on the anodic stripping voltammetry method, the screen-printed biosensor could efficiently detect the cTn markers. Therefore, the biosensor is proposed to be used in clinical settings for fast, sensitive, and accurate monitoring of cTn markers.