New trends in enzyme-free electrochemical sensing of ROS/RNS. Application to live cell analysis

The ubiquity and importance of ROS and RNS in cellular signaling, disease development, and death give rise to an outstanding interest in their detection and quantification. Among the analytical techniques available, electrochemical sensors stand out for the detection of ROS/RNS due to their high sensitivity and inherent miniaturization which allows the in situ and real-time detection together with a tunable selectivity due to the different electrochemical behavior of ROS/RNS. Nanomaterial-based enzyme-free electrochemical sensors possess improved sensitivity, selectivity, stability, and unique catalytic activities. In addition, their integration in nanoelectrodes, lab-on-chips, microfluidic systems, and stretchable electrodes allow the determination of ROS/RNS in individual cells, cell organelles, or cell populations, under different experimental conditions hardly accessible using classical detection methods. Graphical abstract