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

MARÍA L. RAMÍREZ; CECILIA S. TETTAMANTI; FABIANA A. GUTIERREZ; JOSE M. GONZALEZ-DOMÍNGUEZ; ALEJANDRO ANSÓN-CASAOS; JAVIER HERNÁNDEZ-FERRER; MARÍA T. MARTÍNEZ; RIVAS, G. A

MICROCHEMICAL JOURNAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018

0026-265X

his work aims at the development of an electrochemical affinity biosensor for Pb(II) quantification using a platformthat 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 ofPb(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 linearsweep-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 extendsfrom 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 hi