Potentiometric sensors based on the inductive effect on the pK(a) of poly(aniline): a nonenzymatic glucose sensor

Potentiometry is an analytical technique that measures the potential difference between two electrodes in an electrochemical cell without drawing any significant current that could alter the solution's composition. This method employs an indicator electrode, which exchanges electrons with the analyte solution, and a reference electrode with a constant potential. Each electrode is immersed in a solution comprised of two half-cells. In a conventional setup, the reference electrode serves as the...

Reference electrodes serve as a stable reference point for potentiometric measurements, while indicator and working electrodes react to variations in the composition of a solution.
The Standard Hydrogen Electrode (SHE) is a widely used reference electrode that maintains zero potential across all temperatures. However, its need for a continuous hydrogen gas supply renders it impractical for everyday use.
An alternative to SHE is the Saturated Calomel Electrode (SCE). This electrode features an...

Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...

Amperometry is a technique commonly used to measure the concentration of specific analytes in a solution by monitoring the electric current generated during an electrochemical reaction. It involves applying a constant potential between a working electrode and a reference electrode to measure the resulting current, which is proportional to the concentration of the analyte. The Clark oxygen electrode operates based on this principle of amperometry. It consists of a cathode and an anode enclosed...

The perception of a salty flavor is facilitated by sodium ions within the oral salivary fluid. Upon consumption of a salty substance, salt crystals disassemble, leading to the liberation of its constituents—Na+ and Cl- ions. These ions subsequently dissolve into the salivary fluid present in the oral cavity. The external environment of the gustatory cells experiences an elevation in Na+ concentration, thereby establishing a potent concentration gradient. This gradient propels the diffusion of...

Microbial biosensors are analytical devices that utilize living microbes to detect specific substances through measurable signals. These devices consist of two main components: biosensing organisms and signal-transducing elements. Biosensing organisms, such as Escherichia coli or Saccharomyces cerevisiae, are typically housed in multiwell plates connected to transducers, enabling rapid, real-time detection of target analytes.Signal Generation MechanismWhen a target analyte—such as...