Electrochemical Biosensors for Cardiovascular Diseases’ (CVDs) Biomarkers Detection ^†

Cardiovascular diseases (CVDs), a group of diseases related to heart and blood vessel disorders, are the main health problem worldwide. Therefore, the development of modern diagnostic technologies for the rapid and accurate detection of cardiac biomarkers has recently become of high significance. Sensitive protein biomarker identification can help to prevent and slow down CVD progression. The ability of electrochemical biosensors to determine cardiovascular biomarkers, such as cardiac troponin I (cTnI), brain natriuretic peptide (BNP-32) and low-density lipoprotein (LDL), in the serum of patients is crucial for the development of point-of-care sensing platforms. Electrochemical biosensors, cheap and scalable devices, offer, moreover, attractive alternatives for conventional immunoassays. In our group, we joined this research line and, in this presentation, we report on:

• Electrochemical aptasensors for the detection of BNP-32 and cTnI using differential pulse voltammetry (DPV) in Phosphate buffer saline (PBS) and [Fe(CN)₆]⁴⁻, based on screen-printed gold electrodes modified electrophoretically with (1) polyethyleneimine/reduced graphene films, (2) subsequently with propargylacetic acid, and (3) azide-terminated aptamers immobilized using Cu(I)-based “click” chemistry on propargyl groups;
• The comparison of electrochemical immuno- and aptasensor for the detection of LDL using square-wave voltammetry (SWV) in PBS containing [Fe(CN)₆]^3−/4−, an immunosensor based on anti-apolipoprotein B-100 antibody covalently attached to 4-aminothiophenol (4-ATP) on the surface of the gold electrode and an aptasensor based on the gold electrode modified in a mixture of 6-mercaptohexanol and ssDNA aptamer specific for the LDL-containing -SH group;
• Studies on the application of monoclonal antibodies against LDL labelled with redox-active molecules (derivatives of ferrocene) immobilized on the surface of the gold electrode for the detection of LDL based on changes in ferrocene redox activity.