Modified Screen Printed Electrode Suitable for Electrochemical Measurements in Gas Phase

Abstract

We describe a convenient assembly for screen printed carbon electrodes (SPCE) suitable for analyses in gaseous samples which are of course lacking in supporting electrolytes. It consists of a circular crown of filter paper, soaked in a RTIL or a DES, placed upon a disposable screen printed carbon cell, so as to contact the outer edge of the carbon disk working electrode, as well as peripheral counter and reference electrodes. The electrical contact between the paper crown soaked in RTIL or DES and SPCE electrodes is assured by a gasket, and all components are installed in a polylactic acid holder. As a result of this configuration, a sensitive, fast-responding, membrane-free gas sensor is achieved where the real working electrode surface is the boundary zone of the carbon working disk contacted by the paper crown soaked in the polyelectrolyte. This assembly provides a portable and disposable electrochemical platform, assembled by the easy immobilization onto a porous and inexpensive supporting material such as paper of RTILs or DESs which are characterized by profitable electrical conductivity and negligible vapor pressure. The electroanalytical performance of this device was evaluated by voltammetric and flow injection analyses of oxygen which was chosen as prototype of electroactive gaseous analytes. The results obtained pointed out that this assembly is very profitable for the analysis of gaseous atmospheres, especially when used as detector for FIA in gaseous streams.

Amperometric Detection of Ethanol Vapors by Screen Printed Electrodes Modified by Paper Crowns Soaked with Room Temperature Ionic Liquids

“…This fact can easily be explained on considering that the effective electrode area available at these modified SPE electrodes was not that of the entire gold working electrode. In fact, it corresponded only to the outer edge of this electrode intimately contacted by the soaking electrolyte present in the boundary zone of the paper crown, where ethanol vapors undergo charge transfer as soon as they reach the relevant interphase [36].…”

“…Modified SPEs were assembled as reported elsewhere [36], by profiting from a polylactic holder constructed on purpose by the fused deposition modeling technology using a FLSUN Cube 3D printer Ultimaker 2 (Ultimaker B.V., The Netherlands) loaded with a commercially available polylactic filament (FacilanTM Ortho Natural Elogiam, Filoprint, IT). This holder consisted of an upper and a lower portion, as shown in Figure 1A.…”

“…Recently, the assembly of RTIL-based electroanalytical gas-sensors was made significantly easier by suggesting a very simple modification of low-cost disposable devices such as screen printed electrodes (SPEs) [34,35]. This modification involves the simple application on the surface of three-electrode screen-printed devices of a conveniently shaped paper sheet soaked with a suitable RTIL [36]. This device was only tested for the reduction of oxygen, chosen as proof of concept, but no real application was so far reported.…”

Paper-based aptamer-antibody biosensor for gluten detection in a deep eutectic solvent (DES)

“…Among the most relevant points in the use of this material, there are advantages such as biocompatibility and biodegradability, low cost, and ease of production [12]. These aspects have led to a growing interest in the development of paper-based analytical devices (PADs), such as smart labels [13], gas sensors [14,15], and sensors combining electrochemical and visual readouts [16]. PADs have successfully found application in diagnostics [4], environmental monitoring [17], and food control [18].…”

Hand-Held and Integrated Tubular Tip-like Sensing Platform Series: Point-of-care Device for Semi-automated Multiplexed Assay

“…Specifically, their electrochemical interface is built on the planar electrode (PE), which would result in limited and fixed sensing area and insufficient utilization of sample solution (Figure S2). , Besides, in most cases, detection is carried out in an open chamber, leaving sample solution in direct contact with the external circumstance, which may cause solution evaporation and contamination.…”