Biopolymer-Modified Carbon Paste Electrode for the Electrochemical Detection of Pb(II) in Water

Abstract

During the present study, biopolymer lignin was extracted, in particular, from sugar beet pulp (molasses) from the Tadla region (224 km from Marrakech, Morocco). The lignin was characterized by infrared spectroscopy (FTIR) and thermogravimetric TG/DTA analysis and then used as a modifier to enhance the electroanalytical detection of heavy metal ion traces. The performance of the lignin/CPE sensor to detect lead (II) was studied by cyclic voltammetry (CV) and square-wave voltammetry in 0.3 mol L−1 NaCl. With optimized experimental parameters, the lignin/CPE sensor developed has a minimum detection limit of 2.252.10−11 M for Pb (II). The proposed working electrode has been successfully applied for the coanalysis of Pb (II) in tap water with good results.

Recent advances in the modification of electrodes for trace metal analysis: a review

“…A combination of two polymers (i.e., conductive polydopamine (PDA) doped PPy hydrogel) as modifiers of an SPCE for the determination of Pb 2+ has also been reported. 232 Biopolymers (mainly chitosan and different forms of cellulose) 35,37,61,69,[71][72][73]87,89,92,123,124,175,186,187,197,[200][201][202][203][204][205] (further discussed in section 7) and Nafion (a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer) 24,62,108,113,149,154,155,179,200,[233][234][235][236][237][238][239][240][241] are by far most frequently used as polymeric components of the nanocomposites. Moreover, other conducting polymers such as polyaniline (PANI), 23,38,99,102,122,…”

“…123 These compounds are rich in functional groups such as hydroxyl, carboxyl, and sulfonic groups, which bind the analytes and help facilitate the combination of different modifiers. 69,71,72,92 Chitosan, 35,37,61,73,87,89,123,124,175,186,187,197,201 modified cellulose, bacterial cellulose and carboxymethyl cellulose (CMC), 69,71,202,203 lignosulfonate, 92 chitin, 204 lignin, 205 and κ-carrageenan 72 are among the biopolymers used to modify the electrodes.…”

“…Although the vast majority of the studies reported on the combined use of polymers and other materials and/or molecules to modify the electrodes, 22,23,26,29,32,35,37,38,41,45,61,69,71–73,77,80,84,87,89,91,92,94,96–102,106,122–124,131,141–144,175,176,182–184,186,187,197,200–221 there is also a significant number of studies on polymers as sole modifiers. 174,185,222–232 These exceptions include, among others, the pure polymer film-modified electrodes discussed in section 4.…”

“…Biopolymers (mainly chitosan and different forms of cellulose) 35,37,61,69,71–73,87,89,92,123,124,175,186,187,197,200–205 (further discussed in section 7) and Nafion (a sulfonated tetrafluoroethylene-based fluoropolymer–copolymer) 24,62,108,113,149,154,155,179,200,233–241 are by far most frequently used as polymeric components of the nanocomposites. Moreover, other conducting polymers such as polyaniline (PANI), 23,38,99,102,122,144,183,206–209,220 PPy, 32,77,80,96,101,210–212,214,216 and poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives, 58,174,217 as well as PDA, 98,182 have also been part of the nanocomposites used to modify electrodes for trace heavy metal analysis.…”

“…In the last five years, several research groups have continued to explore the inclusion of various environmentally friendly (green) modifiers in the development of new electrodes for trace metal analysis. 23,35,37,61,66,69,71–73,87,89,92,104,110,120–127,157,175,186,187,197,201–205,219,289,293,313–321 Table S6 in the ESI† summarizes the main findings of the research studies published in the last five years reporting on the use of different green modifiers for various types of electrodes employed in the determination of trace heavy metals.…”