Cysteine functionalized bio-nanomaterial for the affinity sensing of Pb(II) as an indicator of environmental damage

TETTAMANTI, CECILIA; RODRÍGUEZ, MARCELA C.; MARTINEZ, MARÍA T.; GUTIERREZ, FABIANA A.; RAMÍREZ, MARÍA L.; GONZALEZ-DOMINGUEZ, ALEJANDRO; RIVAS, GUSTAVO A.; HERNANDEZ-FERRER, JAVIER

MICROCHEMICAL JOURNAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018 vol. 141 p. 271 - 278

0026-265X

This work aims at the development of an electrochemical affinity biosensor for Pb(II) quantification using a platform that combines glassy carbon electrodes (GCE) and an aqueous dispersion of single-walled carbon nanotubes (SWCNT) covalently modified with cysteine residues (Cys). The biosensing protocol includes the accumulation of Pb(II) at the electrode surface through the affinity interaction promoted by Cys residues at open circuit potential, followed by the reduction of the accumulated Pb(II) at ‐0.900V and the transduction step performed by linear sweep-adsorptive stripping voltammetry (LSAdSV) in a 0.020M acetate buffer solution pH5.00. There is a linearrelationship between Pb(II) oxidation peak current and Pb(II) concentration. The dynamic linear range extends from 5.0 to 125.0μg·L⁠−1, exhibiting a sensitivity of 0.061μAμg⁠−1L and a detection limit of 0.69μg·L⁠−1. In addition,the selectivity of the biosensor was evaluated in the presence of high concentrations of possible interferents such as Cu(II), Cd(II), Ni(II), Hg(II), Rh(II), Ru(II), Zn(II), Ir(IV), Co(II) and As(III) demonstrating a high discrimination of Pb(II) in complex samples. The sensor was challenged with tap and rain water samples enriched with Pb(II), demonstrating outstanding properties in terms of recovery percentages showing an excellent agreementwith ICP- MS.