A novel molecularly imprinted polymer PMB/MWCNTs sensor for highly-sensitive cardiac troponin T detection

Cardiac troponin T (cTnT) is a cardiac biomarker introduced for early diagnosis, patient follow-up and guidelines for acute myocardial infarction treatment. In this work a novel cTnT-molecularly imprinted polymer (MIP) based electrochemical sensor using a screen printed carbon electrode (SPCE) was developed. The MIP sensor employed an electrodeposited polymethylene blue (PMB) redox probe on multi-walled carbon nanotubes (MWCNTs) modified SPCE, with the electropolymerized polyaniline around the immobilized cTnT templates. The sensor response was performed using differential pulse voltammetry, wherein the decrease in the PMB current correlated with an increase in the concentration of cTnT. Linearity was obtained in the range of 0.10-8.0 pg mL(-1) with a detection limit of 0.040 pg mL(-1). The MIP sensor exhibited an excellent binding affinity (K-D = 2.8 x 10(-13)mol L-1), high selectivity and good stability, whilst retaining more than 90 % of the sensitivity after 6 weeks of storage at room temperature. The determination of cTnT in human plasma using the developed sensor compared well with the gold standard electrochemiluminescense method (P > 0.05). This novel cTnT-MIP sensor provides a high potential for the development of cTnT point-of-care testing applications.