Improving accuracy and reliability of an electrochemical impedance spectroscopy aptamer-based biosensor

Abstract

Abstract Impedance-based biosensors are effective tools for rapid and specific detection. However, they often rely solely on charge transfer resistance as an indicator of surface structural changes upon analyte binding and other valuable data are constantly ignored. In this work we explore different data obtained for a biosensor designed for water toxin (Saxitoxin) detection using electrochemical impedance spectroscopy. We established a safe potential range for ensuring sensor stability using cyclic voltammetry and determined the potential where the constant phase element values were more pronounced. The data showed that capacitance values could not reliably evaluate the system due to their high deviations. The impedance modulus (Z) revealed the highest number of acceptable frequencies and the values of the imaginary impedance (-Z") exhibited signal differences exceeding 30%, indicating their potential for signal enhancement during saxitoxin detection. The relative standard deviation can be reduced by increasing the concentration of the redox probe. The obtained results highlight the importance of carefully selecting parameters for characterizing the electrochemical behavior of the system to identify the most reliable and informative parameters for detection. This research contributes to broader electrochemistry sensing applications, opening new horizons for improving the accuracy and reliability of electrochemical analysis.