An ultrasensitive human cardiac troponin T graphene screen-printed electrode based on electropolymerized-molecularly imprinted conducting polymer

• Published in: Biosensors & bioelectronics Vol. 77; pp. 978 - 985
• Main Authors: Silva, Bárbara V.M., Rodríguez, Blanca A.G., Sales, Goreti F., Sotomayor, Maria Del Pilar T., Dutra, Rosa F.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15-03-2016
• Subjects: Acid carboxylic-3-pyrrole; Biomimetics; Cardiac troponin T; Conductometry - instrumentation; Electric Conductivity; Electrodes; Electroplating - methods; Equipment Design; Equipment Failure Analysis; Graphene; Graphite - chemistry; Humans; Immunoassay - instrumentation; Molecular Imprinting - methods; Molecularly imprinted polymer; Nanostructure; Photography - methods; Point-of-care testing; Pyrrole; Pyrroles; Reproducibility of Results; Sensitivity and Specificity; Surface chemistry; Three dimensional; Troponin T - blood; Voltammetry; Point-of-care testing; Acid carboxylic-3-pyrrole; Graphene; Molecularly imprinted polymer; Cardiac troponin T; Pyrrole
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2015.10.068

A nano-molecularly imprinted polymer (N-MIP) assembled on a screen-printed electrode for the cardiac troponin T (cTnT) was developed. The biomimetic surface was obtained by a co-polymer matrix assembled on the reduced graphene oxide (RGO) electrode surface. The cTnT active sites were engineered using pyrrole and carboxylated pyrrole that was one-step electropolymerized jointly with cTnT by cyclic voltammetry. The stepwise preparation of the biomimetic surface was characterized by cyclic and differential pulse voltammetries using the ferrocyanide/ferricyanide as redox probe. Structural and morphological characterization was also performed. The optimal relation of pyrrole and pyrrole-3-acid carboxylic to perform the cTnT biomimetic nanosurface was obtained at 1:5 ratio. The analytical performance of cTnT N-MIP performed by differential pulse voltammetry showed a linear range from 0.01 to 0.1ngmL−1 (r=0.995, p«0.01), with a very low limit of detection (0.006ngmL−1). The synergic effect of conductive polymer and graphene forming 3D structures of reactive sites resulted in a N-MIP with excellent affinity to cTnT binding (KD=7.3 10−13molL−1). The N-MIP proposed is based on a simple method of antibody obtaining with a large potential for point-of-care testing applications.
•A biomimetic sensor as imprinted thin-film was developed to cardiac troponin T.•A sensor was assembled based on graphene and conductive polymer synergism.•The biomimetic sensor was assembled onto a disposable screen-printed electrode.•The functionalized pyrrole was explored to mimetizes the cTnT antibodies.•The biomimetic cTnT sensor achieved a good limit of detection (0.006ngmL−1).