An Electrochemical Immunosensor Based on GO@CS for Highly Sensitive and Accurate Detection of Cardiovascular Markers-cTn- I

The hidden hazards of cardiovascular diseases (CVDs) are enormous, and there is a lack of early warning and prognostic risk assessment technologies. In this study, Cardiac troponin I (cTn-I), the “gold standard” for CVDs diagnosis, was selected as the target molecule, and chitosan functionalized graphene oxide composites (GO@CS) with excellent electrochemical performance were prepared as the electrode base material. Gold nanoparticles (AuNPs) were deposited on GO@CS by electrochemical deposition. Due to the large surface area, excellent electrical conductivity and good biocompatibility of GO@CS assembled with AuNPs provide abundant active sites for the immobilization of cTn-I antigen. Under the optimized experimental conditions, the fabricated immunosensor had a wide linear range of 2.44 × 10 −2 ng ml −1 to 2.50 × 10 ng ml −1 and a low detection limit of 1.12 × 10 −2 ng ml −1 (S/N = 3). This study achieves the highly sensitive identification and detection of trace amounts of cTn-I in complex biological samples, providing a convenient and efficient method for the detection of CVDs-related markers. It also provides a scientific basis, new technologies and new methods for the development of objective early warning techniques for CVDs and the study of related pathological mechanisms.