在生物流体中检测小分子:电位计生物传感器的新兴作用

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...

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...

Potentiometric titration is a quantitative analytical technique that determines the concentration of an analyte by measuring the potential difference between the two electrodes in the solution. The endpoint of a potentiometric titration is the point at which there is a significant change in the potential difference. It occurs when the stoichiometric reaction between the analyte and the titrant is complete. The endpoint is usually determined graphically by plotting the measured potential...

The role of the detectors in High-Performance Liquid Chromatography (HPLC) is to analyze the solutes as they exit from the chromatographic column. The detector recognizes the solute's property and generates corresponding electrical signals, which are converted into a readable graph of the detector's response versus elution time called a chromatogram at the computer. There are several types of HPLC detectors, each with its own advantages and limitations, depending on the analyte...

Controlled-potential coulometry, also known as potentiostatic coulometry, employs a three-electrode system in which the working electrode's potential is precisely regulated using a potentiostat. Platinum working electrodes are utilized for positive potentials, while mercury pool electrodes are favored for extremely negative potentials. The platinum counter electrode is separated from the analyte using a membrane or salt bridge to avoid interference in the analysis.
The chosen potential...