Microelectrodes advantages

FSCV Same microelectrode advantages Faster electron transfer and higher mass sensitivity Improved temporal resolution <1 msec 8 10 nM [119,120]... 

Miniaturization is a growing trend in the field of analytical chemistry. The miniaturization of working electrodes not only has obvious practical advantages, but also opens some fundamentally new possibilities (77-79). The term microelectrode is reserved here for electrodes with at least one dimension not greater than 25 pm. 

A. Brunet, C. Privat, O. Stepien, M. David-Dufilho, J. Devynck, and M.A. Devynck, Advantages and limits of the electrochemical method using Nafion and Ni-porphyrin-coated microelectrode to monitor NO release from cultured vascular cells. Analusis 28, 469 (2000). 

In the case of a single electrode, however, the decrease of its dimensions requires the measurement of very low currents. To overcome this problem it is convenient to use microelectrode arrays [136, 137], Despite the fact that in such arrays microelectrodes are electronically connected to each other, analytical properties of such assemblies are advantageous over those of a conventional macro-electrode [138, 139],... 

Even though their fabrication is difficult, microelectrodes have a number of advantages over other methods ... 

The advantages of such electrodes goes beyond the simple restrictions borne of size. The major advantages of microelectrodes follow from their geometry - the electrode is in fact a fine wire encased within an unreactive sheath of plastic, thus ensuring that only one of its end faces is in contact with the solution. This end is typically flat and circular with a diameter of 0.5-50 pm. 

The analyte addition method (AAM) involves adding the sample solution to a standard solution of the determinand, whereas in the analyte subtraction method (ASM) the sample is added to a standard solution of an ion that reacts stoichiometrically with the test substance and is sensed by an ISE. These methods are advantageous for determinations on small samples for which microelectrodes would otherwise have to be used. pH adjustment and masking of interferents in the sample is unnecessary because all these operations can be done beforehand on the standard solution. Furthermore, the analyte subtraction method widens... 

Another advantage in the use of microelectrodes is that the limiting diffusion current is independent of disturbances in the solution. Thus, for a planar electrode, the... 

A practical use of a microelectrode The advantages of microelectrode techniques are especially pronounced for systems with limited conductivity (e.g., polymer electrolytes), which are popular candidates for state-of-the-art lithium ion batteries, normally with room-temperature conductivities K - 10-4 S/cm. (a) A researcher is evaluating a newly synthesized lithium polymer electrolyte. He uses a two-electrode cell in which an electrolyte disk of 0.1 cm X 1.0 cm is... 

Earlier it was pointed out that the use of ultramicroelectrodes could also give a several hundred times increase in iL compared with the diffusion-free currents at planar electrodes. The advantage of increasing the ability to measure at higher current densities by using short times in a transient technique with a planar electrode is that the magnitude of the currents is normal and is not forced down to the difficult-to-measure picoampere region that microelectrodes require. 

What are the advantages of using a microelectrode for voltammetric measurements ... 

A major advantage of microelectrodes is that electrochemical data is less distorted by ohmic drop than when recorded with electrodes of conventional size... 

Advantages are also found with microelectrodes used at short time scales where time-dependent currents are obtained, as the example in Figure 12.4 shows [56]. Time-dependent currents are proportional to the electrode area. Thus, for the case of a sphere, combination of the expression for the time-dependent current with the resistance shows that the ohmic drop is directly proportional to the radius. Thus, ohmic drop is always minimized by the use of a smaller electrode. 

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