Coordination matrix/signal amplifier strategy for simultaneous electrochemical determination of cadmium(ii), lead(ii), copper(ii), and mercury(ii) ions based on polyfurfural film/multi-walled carbon nanotube modified electrode

• Published in: RSC advances Vol. 7; no. 45; pp. 28556 - 28563
• Main Authors: Huang, Jianzhi, Bai, Silan, Yue, Guoqing, Cheng, Wenxue, Wang, Lishi
• Format: Journal Article
• Language: English
• Published: 30.05.2017
• Subjects: cadmium; carbon nanotubes; copper; electrochemistry; glassy carbon electrode; heavy metals; lead; mercury; metal ions; sensors (equipment); tap water
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c7ra04029f

In this work, we firstly propose and confirm a novel coordination matrix/signal amplifier strategy to construct a highly sensitive lead( ii ) electrochemical sensor. Lead( ii ) ions can be efficiently accumulated and deposited on the electrode surface by strong coordination bonds between the unoccupied d-orbital of lead( ii ) ions and conjugated π-electron backbones of polyfurfural film (coordination matrix), and then the anodic stripping current can be significantly enhanced by multi-walled carbon nanotubes (MWCNTs, signal amplifier), finally realizing the highly sensitive determination of lead( ii ). The polyfurfural film/MWCNT modified glassy carbon electrode (GCE) sensor provided a wide linear detection range from 0.05 to 10 μg L −1 and a low detection limit of 0.01 μg L −1 (S/N = 3) for lead( ii ). Compared with a classical mercury film sensor (a classical and effective method for determining heavy metal ions), our proposed sensor was more sensitive and achieved better results. Moreover, based on the coordination matrix/signal amplifier strategy, the polyfurfural film/MWCNTs/GCE sensor was further successfully utilized for the simultaneous determination of Cd 2+ , Pb 2+ , Cu 2+ , and Hg 2+ , demonstrating a wide linear detection range for Cd 2+ (0.5-15 μg L −1 ), Pb 2+ (0.1-15 μg L −1 ), Cu 2+ (0.1-12 μg L −1 ), and Hg 2+ (1.5-12 μg L −1 ) and a low detection limit for Cd 2+ (0.03 μg L −1 , S/N = 3), Pb 2+ (0.01 μg L −1 , S/N = 3), Cu 2+ (0.06 μg L −1 , S/N = 3), and Hg 2+ (0.1 μg L −1 , S/N = 3). Finally, the proposed sensor was successfully applied to simultaneously determine Cd 2+ , Pb 2+ , Cu 2+ , and Hg 2+ in real tap water samples. This work provides a novel and effective analytical strategy for constructing novel electrochemical sensors and shows broad application prospects in heavy metal ion determination for the future. Coordination matrix/signal amplifier strategy for simultaneous electrochemical determination of cadmium( ii ), lead( ii ), copper( ii ) and mercury( ii ) ions based on polyfurfural film/multi-walled carbon nanotubes modified electrode.