Yes, effective cleaning helps to improve the binding properties of the materials and enhance electrochemical performance by increasing surface area.

The Counter Electrode (CE) in SPE is made up of carbon ink because of the low cost and inertness. The main purpose of the CE is to maintain electrical neutrality and it helps to complete the circuit. The Working Electrode (WE) is usually made up of silver, gold, or other metals inks based on the application or target analyte as it must be sensitive to analyte concentration. Silver and silver chloride mixture ink is commonly used to print  Reference Electrodes (RE) because of their low cost and easy availability. These silver/silver chloride inks are good conductors and it is very...

SPEs are extensively used for electrochemical sensing applications because of their accuracy, sensitivity, and reproducibility. These are inexpensive to mass-produce and they can be used as basic transducers. Additionally, they come in a variety of shapes including a ring, a disc, or a band for different applications.

SPEs are widely used in electrochemical analysis by researchers, scientists, industrialists, and quality control analysts to develop electrochemical sensors, point-of-care devices for biomedical applications and environmental monitoring.

Screen Printed Carbon Electrodes are used only in aqueous regions and their thermal stability ranges from 10°C to 80°C depending upon the substrates used such as plastics since they are of low cost. Whereas, Gold and platinum screen-printed electrodes are used in both aqueous and non-aqueous regions and their thermal stability ranges from 10°C to 200°C since they are fabricated on ceramics.

Screen Printed Electrodes (SPE) are fabricated by printing on non-conductive materials like alumina, ceramic, and plastic which serves as the electrode's support. It consists of three electrodes namely, the working electrode (WE), Counter electrode (CE), and Reference electrode (RE), and these electrode surfaces are coated with various conductive inks like, WE (carbon, platinum, or gold inks) CE (Carbon ink) RE (silver/silver chloride ink) The electrochemical performance, selectivity, and sensitivity of the SPE based sensors are determined by different conductive inks like Platinum, Gold, Silver, and Carbon.

In general, inert nature of the platinum does not result in contamination, and washing with distilled water post-experimentation is sufficient. However, contamination can occur over time in the presence of strong acidic or alkaline solutions. In such cases, Piranha solution can be used to clean the contaminated platinum electrode. It is a mixture of sulfuric acid and hydrogen peroxide (1:3). Another method used to clean the counter electrode is to immerse the electrode in 10% nitric acid solution.

Platinum or Carbon as counter electrode material is preferred because both require low maintenance and don't easily get oxidized or reduced. Platinum: Platinum, due to its inertness and electrical conductivity, is found to be one of the best counter-electrode materials. Platinum electrodes are available in different forms such as - mesh, foil, wire, and tip. Based on experimental requirements, different forms of platinum electrodes are employed and a mesh kind of platinum electrode is widely used due to its high surface area and porous nature. Limitations: Cost-effective Carbon (graphite rods): Graphite rods are more affordable than platinum, have higher corrosion...

The counter electrode must be made up of inert metals like gold, platinum, or carbon species. It should have a large surface area, to enable a high current flow even with low potentials. Also, in general, counter electrode size is maintained slightly larger than the working electrode as it enhances measurement accuracy, minimizing the energy losses and the influence of electrolyte resistance.

The Counter Electrode serves two crucial roles, it completes the circuit and maintains electrical neutrality and it protects the reference electrode from any other potential changes. The main function of CE is to promote electron flow while minimizing any undesirable polarisation effects.

When GCE is used in an acidic medium, it produces surface oxides through an acid-catalyzed process, resulting in activation of the GCE surface and causing bulk oxidation. In alkaline media, The carbon layers become hydrophilic and dissolve as a result of oxidation.

High anodic potentials leads to oxidation of carbon and affect the catalyst's electrochemical performance on the surface of the modified GCE. However, in some cases, such oxidations activate the modified GCE surface and enhance the rate of electron transfer in the resulting redox process.

There are 3 different sizes of alumina powder for polishing the GCE surface namely 1.0, 0.3, and 0.05 microns. Alumina with a particle size of 0.05 micron is commonly used. After polishing the electrode surface with 0.05 micron slurry, if some scratches or residues are still found on the electrode surface, continue polishing using 1.0, 0.3, and 0.05 microns in a sequence. The resulting GCE surface will be mirror-shiny.

Position the GCE vertically and aim it towards the alumina slurry existing in the glass pad, drawing a continuous 8 line in the pad with mild pressure as shown in      Fig 1, and not a zigzag or horizontal line as shown in Fig 2 and 3. Wash the polished GCE using distilled water (DI) followed by sonication for few minutes using acetone/ ethanol, or DI water.

Yes, polishing of GCE is highly recommended prior to the experimentation using alumina and diamond slurries to obtain clean and uniform surface. Also, to remove the residues of the previous experiments. In this way, the repeatability, sensitivity, and stability of the electrode can be improved. It could be feasible to utilize a GCE without polishing but the surface of the electrode is awry, which could lead to inconsistent electrochemical performance.

In general, Glassy Carbon Electrode (GCE) is the preferred working electrode in electrochemistry because of their chemical inertness, easy fabrication, high hardness, wide range potential, high electrical conductivity, low capacitance, and low current background. GCE is made of amorphous, non-graphitic carbon that has been thoroughly purified. Due to its low reactivity (high corrosion resistance) makes a flexible option for most of the electrochemical applications.

Vycor frit can be cleaned and reused by using a small blub or other suction device, forcibly pressurize the inner volume of water slightly to cause drainage out the frit. If the contamination increases over time, cleaning them is a challenging process, therefore we must replace the frit for better results. If the frit is broken, cracked, or soiled, as seen in Figure 1, it cannot be reused.

The porous frit at the tip of the reference electrode (RE) acts as a semi-permeable membrane facilitating ions exchange between RE’s filling solution (3M NaCl/KOH) and electrolyte while avoiding direct physical interaction between the two as shown in Fig 1. The primary function of the frit is to lower the leak rate and to determine the stability of the reference electrode (RE) while using a potentiostat. The reference electrode without frit tip will lead to electrolyte contamination. For example, A junction potential arises at the interface of two ionic solutions due to differences in the compositions, concentrations, and mobility of...

Listed below is a comparative study between Saturated Calomel Electrode (SCE) and Silver - Silver Chloride Electrode (Ag/AgCl):    Sl.No  Features/Category  Saturated Calomel Electrode (SCE) Silver - Silver Chloride Electrode (Ag/AgCl)  1   Notation    Hg|Hg2Cl2, KCl(aq), (sat)    Ag|AgCl, KCl(aq), (sat)  2   Filling solution    Saturated KCl    3M KCl  3   Potential Vs SHE    +0.241V Sat KCl +0.197 V Un sat KCl +0.205 V  4   Advantages Easy to setup and reproducible. Wider potential range. Convenient and easy to transport. No need of salt bridge Simple and stable Non-toxic  5   Disadvantage    Toxic Short lifetime and light-sensitive  6  ...

Make sure the electrode is free from contamination and it is clean. To achieve equilibrium, immerse the electrode in a 3M (KCl/NaOH) solution. Choose the standard reference electrode with known potential. As illustrated in Fig 1, place both electrodes in a cell containing saturated 3M (KCl/NaOH) and connected to a voltmeter. It is useful for determining the potential of the reference electrode. If the voltage value is zero, the reference electrode is functioning properly. If the voltage value is non-zero or near to zero, the difference is very small and it may be acceptable. If the voltage value fluctuates more...