current waveform derived by subtracting the reverse current waveform from the forward current waveform. This differential curve is then plotted against the applied potential. Peaks in the differential current vs. applied potential plot are indicative of redox processes, and the magnitudes of the peaks in this plot are proportional to the concentrations of the various redox active species according to: where Δip is the differential current peak value, A is the surface area of the electrode, C0* is the concentration of the species, D0 is the diffusivity of the species, tp is the pulse width, and ΔΨp is a dimensionless parameter which gauges the peak height in SWV relative to the limiting response in normal pulse voltammetry. Renewal of diffusion layer It is important to note that in squarewave volammetric analyses, the diffusion layer is not renewed between potential cycles. Thus, it is not possible/accurate to view each cycle in isolation; the conditions present for each cycle is a complex diffusion layer which has evolved through all prior potential cycles. The conditions for a particular cycle are also a function of electrode kinetics, along with other electrochemical considerations. Applications Because of the minimal contributions from non-faradaic currents, the use of a differential current plot instead of separate forward and reverse current plots, and significant time evolution between potential reversal and current sampling, high sensitivity screening can be obtained utilizing SWV. For this reason, squarewave voltammetry has been utilized in numerous electrochemical measurements and can be viewed as an improvement to other electroanalytical techniques. For instance, SWV suppressed background currents much more effectively than cyclic voltammetry - for this reason, analyte concentrations on the nanomolar scale can be registered utilizing SWV over CV. SWV analysis has been used recently in the development of a voltammetric catechol sensor, in the analysis of a large number of pharmaceuticals, and in the development and construction of a 2,4,6-TNT and 2,4-DNT sensor In addition to being utilized in independent analyses, SWV has also been coupled with other analytical techniques, including but not limited to thin-layer chromatography (TLC) and high-pressure liquid chromatography. See also Voltammetry Electroanalytical method References Electroanalytical methods