Development of New Simple Compositions of Silver Inks for the Preparation of Pseudo-Reference Electrodes

Abstract

Silver materials are known to present excellent properties, such as high electrical and thermal conductivity as well as chemical stability. Silver-based inks have drawn a lot of attention for being compatible with various substrates, which can be used in the production uniform and stable pseudo-reference electrodes with low curing temperatures. Furthermore, the interest in the use of disposable electrodes has been increasing due to the low cost and the possibility of their use in point-of-care and point-of-need situations. Thus, in this work, two new inks were developed using Ag as conductive material and colorless polymers (nail polish (NP) and shellac (SL)), and applied to different substrates (screen-printed electrodes, acetate sheets, and 3D-printed electrodes) to verify the performance of the proposed inks. Measurements attained with open circuit potential (OCP) attested to the stability of the potential of the pseudo-reference proposed for 1 h. Analytical curves for β-estradiol were also obtained using the devices prepared with the proposed inks as pseudo-references electrodes, which presented satisfactory results concerning the potential stability (RSD < 2.6%). These inks are simple to prepare and present great alternatives for the development of pseudo-reference electrodes useful in the construction of disposable electrochemical systems.

Addressing Signal Drift and Screening for Detection of Biomarkers with Carbon Nanotube Transistors

“…OCP measurements of pseudo-reference electrodes with respect to Ag/AgCl electrodes (where both are placed in the same solution, as shown in Figure 2D) are typically used to assess the stability of the pseudo-reference electrode, typically with a goal of showing minimal OCP drift over time. 66,67 Though this electrode does show a slight average drift rate of 14 mV/h, this falls within the nominal limit for pseudo-reference electrode stability of ∼30 mV/h (represented by the dashed line) 66 and ultimately bestows enough confidence in the gating ability of this device architecture for use as a biosensor.…”

“…To test the feasibility of using this Pd electrode geometry, the drift rate of the open-circuit potential (OCP) (i.e., the first derivative of the OCP measurement) was compared relative to a traditional Ag/AgCl electrode over the course of 1 h in solution (Figure D,E) using a single representative chip. OCP measurements of pseudo-reference electrodes with respect to Ag/AgCl electrodes (where both are placed in the same solution, as shown in Figure D) are typically used to assess the stability of the pseudo-reference electrode, typically with a goal of showing minimal OCP drift over time. , Though this electrode does show a slight average drift rate of 14 mV/h, this falls within the nominal limit for pseudo-reference electrode stability of ∼30 mV/h (represented by the dashed line) and ultimately bestows enough confidence in the gating ability of this device architecture for use as a biosensor.…”

3D Printed Design‐Assisted Multilayered Graphene Oxide‐Modified Polymer Glucose Sensor

“…Glucose Sensor Fabrication: The sensor is developed in multiple steps and layers. The three-electrode system comprises a 3D printed mask consisting of a quasi-Ag "reference" electrode, [52] GO þ PEDOT:PSS/Ag "counter" electrode, and GO þ PEDOT:PSS/Ag "working" electrode, connected to the instruments, along with their GO and PEDOTPSS variants. For the fabrication part, Ag paste is added in all three channels and allowed to dry.…”