A C-reactive protein immunosensor based on platinum nanowire / titania nanotube composite sensitized electrochemiluminescence.

C-reactive protein (CRP) is one of the important indicators of inflammatory response. It plays as an essential role in diseases such as myocardial infarction and atherosclerosis. A simple and effective label-free electrochemiluminescent (ECL) immunosensor for quantitative detection of CRP is reported. The indium tin oxide coated glass was prefunctionalized with the composite of titania nanotubes and platinum nanowires as the sensing matrix. Then the CRP antibody was immobilized on it, hosted the sensing function owing to its specific binding with CRP caused by immune affinity. The characteristics of the fabricated sensor were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and electron microscopes. The sensor has the advantages of high sensitivity, good selectivity, good reproducibility and low cost. Under the optimal experimental conditions, the response of ECL signal on obtained sensor has a good linear regression toward the logarithm of CRP quantity within the range from 0.05 ng to 6.25 ng with a detection limit of 0.011 ng. The immunosensor is small, convenient to use, and provides a feasible way for domestically rapid detection of CRP. It has a promising future in the precaution of cardiovascular and other diseases.