Immunosensors for human cardiac troponins and CRP, in particular amperometric cTnI immunosensor

In this paper, the review of immunosensors for selected cardiovascular disease markers: human cardiac troponins and human C-reactive protein (CRP) is presented. In particular, (cTnI) amperometric immunosensor for cTnI measurements in the concentration range useful in medical diagnostics, based on the developed earlier human CRP amperometric immunosensor, is described. The human cTnI is recommended as one of specific myocardial damage biomarkers, and is considered as the “gold standard”, whereas the human CRP is used as the powerful, nonspecific, supplementary biomarker of cardiovascular disease. Carbon, graphite and platinum pastes, used for fabrication of our immunosensor working electrode (WE), were investigated. In the developed simple measuring procedure, based on a direct solid phase enzyme-linked immunosorbent assay (ELISA), for the first time ascorbic acid monophosphate was used for cTnI detection as a substrate in enzymatic reaction of alkaline phosphatase labelling antibodies. Disposable amperometric graphite immunosensors, made on polyester film by means of microdispensing robot, suitable for determination of cTnI in the concentration range 0–35 μg/L with the sensitivity 0.67 μA/(μg/L) and linear correlation coefficient 0.91 were obtained.