Covalent functionalization of single-walled carbon nanotubes with polytyrosine: Characterization and analytical applications for the sensitive quantification of polyphenols

EGUÍLAZ, MARCOS; GONZÁLEZ-DOMÍNGUEZ, JOSE MIGUEL; FERREYRA, NANCY F.; GUTIERREZ, FABIANA; HERNÁNDEZ-FERRER, JAVIER; RIVAS, GUSTAVO; GUTIÉRREZ, ALEJANDRO; ANSÓN-CASAOS, ALEJANDRO; MARTÍNEZ, MARÍA T.

ANALYTICA CHIMICA ACTA

ELSEVIER SCIENCE BV

Año: 2016 vol. 909 p. 51 - 59

0003-2670

This work reports the synthesis and characterization of single-walled carbon nanotubes (SWCNT) covalently functionalized with polytyrosine (Polytyr); the critical analysis of the experimental conditions to obtain the efficient dispersion of the modified carbon nanotubes; and the analytical performance of glassy carbon electrodes (GCE) modified with the dispersion (GCE/SWCNT-Polytyr) for the highly sensitive quantification of polyphenols. Under the optimal conditions, the calibration plot for the amperometric response of gallic acid (GA) shows a linear range between 5.0 × 10-7 and 1.7 × 10-4 M, with a sensitivity of (518 ± 5) m AM-1 cm-2, and a detection limit of 8.8 nM. The proposed sensor was successfully used for the determination of total polyphenolic content in tea extracts.