LAUSR

Abstract This paper describes the development of an immunosensor for the c-reactive protein (CRP), based on both direct and indirect electrochemical detections. The anti-CRP probe was grafted to the platform sensitized with poly(3-aminothiophenol) and the interaction of the CRP target with the immunosensor was carried either directly or indirectly, using 4-aminoantipyrine (4-APP) as indicator. The immunosensor presents a linear response in the range from 75 ng·mL − 1 to 150 μg·mL − 1 and detection limit of 7.24 μg·mL − 1 ( N  = 3). The biosensor specificity, which was determined in the presence of non-specific target is also presented in this paper. Assays realized conducted with real samples indicate that the immunosensor discriminates the serum samples from healthy and sick patients with efficiency. In addition, through atomic force microscopy, it was possible to observe differences between the immunosensor surface in the absence or presence of the CRP target.