Ordinary microfluidic electrodes combined with bulk nanoprobe produce multidimensional electric double-layer capacitances towards metal ion recognition

Author(s):Show less -

da Silva, Giulia S. ^{[1, 2]} ; de Oliveira, Luiza P. ^[1] ; Costa, Gabriel F. ^{[1, 2]} ; Giordano, Gabriela F. ^{[1, 2]} ; Nicoliche, Caroline Y. N. ^[1] ; da Silva, Alexandre A. ^[1] ; Khan, Latif U. ^[1] ; da Silva, Gabriela H. ^{[1, 3]} ; Gobbi, Angelo L. ^[1] ; Silveira, Jose V. ^[4] ; Filho, Antonio G. Souza ^[5] ; Schleder, Gabriel R. ^{[1, 6]} ; Fazzio, Adalberto ^{[1, 6]} ; Martinez, Diego S. T. ^{[1, 3]} ; Lima, Renato S. ^{[1, 2]}

Affiliation

^[1] Brazilian Ctr Res Energy & Mat, Brazilian Nanotechnol Natl Lab, BR-13083970 Sao Paulo, SP - Brazil

^[2] Univ Estadual Campinas, Inst Chem, BR-13083970 Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13416000 Sao Paulo, SP - Brazil

^[4] Univ Fed Ceara, Dept Comp Sci, BR-62010560 Sobral, Ceara - Brazil

^[5] Univ Fed Ceara, Dept Phys, BR-60455900 Fortaleza, Ceara - Brazil

^[6] Fed Univ ABC, Ctr Nat & Human Sci, BR-09210580 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: SENSORS AND ACTUATORS B-CHEMICAL; v. 305, FEB 15 2020.
• Web of Science Citations: 1

Abstract

While multidimensional sensors are powerful platforms towards multitarget analyses, the successive synthesis/fabrication of multiple probes and measurements to each one of these units still damage the device miniaturization, scalability, cost, consumption of samples, operational simplicity, precision, and analysis time. Herein, we describe an electrochemical sensing array that affords the discrimination of metal ions from a single ready-to-use probe and experiment. The sensing probe consisted of commercial stainless-steel capillaries, which defined a microfluidic circuit and acted as electric double-layer parallel capacitors into devices prototyped by a fast, cleanroom-free, and green technique. The probes assured differential responses due to heterogeneous interactions with samples and multichannel capacitance outputs. In addition, we address an effective strategy to further improve the repeatability and recognition ability of the sensor by using oxidized multi-walled carbon nanotubes as a single bulk probe. The nanotubes provided differential electrostatic adsorptions of ions, then increasing the variance of the capacitance responses. The approach was successfully applied in the identification of samples of mineral water, lake, and petroleum according to the presence of metal ions. Using supervised machine learning tasks, the sensor assured reproducible, sensitive, and accurate classification of dozens of lake samples spiked with multiple heavy metals in accordance with their safe limits. Remarkably, simultaneous quantification of the individual concentration of these ions was also possible from universal impedimetric assays by treating the data through multi-output regression. The sensor will be of significance for advanced discriminations from a single ordinary probe and measurement in a direct mode using scalable chips. (AU)

• FAPESP's process: 17/18139-6 - Machine learning for Materials Science: 2D materials discovery and design
• Grantee: Gabriel Ravanhani Schleder
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/00463-1 - 21st World Congress of Epidemiology
• Grantee: Ana Paula Sayuri Sato
• Support Opportunities: Research Grants - Meeting - Abroad
• FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
• Grantee: Adalberto Fazzio
• Support Opportunities: Research Projects - Thematic Grants