Evolution of the analytical signal in electrochemistry from electrocapillary curve to a digital electrochemical pattern of a multicomponent sample

The number of publications on the electrochemical analysis of liquids increases year by year. The growth of publication activity is largely due to the development of new biosensors and the introduction of nanomaterials into the practice of electrochemical analysis. It is not the task of the author to review the entire array of publications, since the basic principles of electrochemical analysis in most publications remain practically unchanged. The purpose of this critical review is to find answers to two important questions for the development of electroanalysis. First, are all of the used electrochemical methods providing a measurement in the strict metrological sense of this term? That is, do they provide the necessary accuracy, validity, reliability, and reproducibility of the measurement results? Secondly, is electroanalytics capable of meeting the challenge of the information revolution by significantly increasing the information efficiency of each individual measurement? To answer these questions, we will identify the main sources of sensor signal noise by considering the electrochemical sensor as the primary decoder of “chemical information” into an analytical signal. Then we will evaluate the information efficiency of various measurement methods by using the approach of thermodynamics of information processes and considering a sensor as an open thermodynamic system.