Bifunctional Metal Meshes Acting as a Semipermeable Membrane and Electrode for Sensitive Electrochemical Determination of Volatile Compounds

Author(s)

Giordano, Gabriela F. ^[1] ; Freitas, Vitoria M. S. ^{[2, 1]} ; Schleder, Gabriel R. ^{[3, 1]} ; Santhiago, Murilo ^{[3, 1]} ; Gobbi, Angelo L. ^[1] ; Lima, Renato S. ^{[4, 3, 1, 5]}

Affiliation

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

^[2] Univ Estadual Campinas, Fac Chem Engn, BR-13083970 Campinas, SP - Brazil

^[3] Fed Univ ABC, BR-09210580 Santo Andre, SP - Brazil

^[4] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil

^[5] Univ Sao Paulo, Sao Carlos Inst Chem, BR-09210580 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: ACS APPLIED MATERIALS & INTERFACES; v. 13, n. 30, p. 35914-35923, AUG 4 2021.
• Web of Science Citations: 0

Abstract

The monitoring of toxic inorganic gases and volatile organic compounds has brought the development of field-deployable, sensitive, and scalable sensors into focus. Here, we attempted to meet these requirements by using concurrently microhole-structured meshes as (i) a membrane for the gas diffusion extraction of an analyte from a donor sample and (ii) an electrode for the sensitive electrochemical determination of this target with the receptor electrolyte at rest. We used two types of meshes with complementary benefits, i.e., Ni mesh fabricated by robust, scalable, and well-established methods for manufacturing specific designs and stainless steel wire mesh (SSWM), which is commercially available at a low cost. The diffusion of gas (from a donor) was conducted in headspace mode, thus minimizing issues related to mesh fouling. When compared with the conventional polytetrafluoroethylene (PTFE) membrane, both the meshes (40 mu m hole diameter) led to a higher amount of vapor collected into the electrolyte for subsequent detection. This inedited fashion produced a kind of reverse diffusion of the analyte dissolved into the electrolyte (receptor), i.e., from the electrode to bulk, which further enabled highly sensitive analyses. Using Ni mesh coated with Ni(OH)(2) nanoparticles, the limit of detection reached for ethanol was 24-fold lower than the data attained by a platform with a PTFE membrane and placement of the electrode into electrolyte bulk. This system was applied in the determination of ethanol in complex samples related to the production of ethanol biofuel. It is noteworthy that a simple equation fitted by machine learning was able to provide accurate assays (accuracies from 97 to 102%) by overcoming matrix effect-related interferences on detection performance. Furthermore, preliminary measurements demonstrated the successful coating of the meshes with gold films as an alternative raw electrode material and the monitoring of HCl utilizing Au-coated SSWMs. These strategies extend the applicability of the platform that may help to develop valuable volatile sensing solutions. (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