The article "Electrochemical Biosensors: Recommended Definitions and Classification" by Daniel R. Thevenot, Klara Toth, Richard Durst, and George S. Wilson provides a comprehensive overview of electrochemical biosensors, including their definitions, classifications, and performance criteria. The authors define an electrochemical biosensor as a self-contained integrated device that uses a biological recognition element (biochemical receptor) in direct spatial contact with an electrochemical transducer to provide specific quantitative or semi-quantitative analytical information. They distinguish electrochemical biosensors from bioanalytical systems, which require additional processing steps such as reagent addition. The classification of biosensors is based on the biological specificity-conferring mechanism or the mode of physicochemical signal transduction. The biological recognition element can be based on biocatalytic reactions or biocomplexing interactions. The transduction modes include amperometry, potentiometry, surface charge using field-effect transistors (FETs), and conductometry. The article also discusses the direct and indirect monitoring of analytes or reactions, the construction of biosensors, and performance criteria such as calibration characteristics, selectivity, response times, sample throughput, reproducibility, stability, and lifetime. It emphasizes the importance of standard protocols for evaluating these criteria and provides guidelines for reporting the characteristics of biosensor responses. The authors recommend that the term "biosensor" should be clearly distinguished from "bioanalytical system" and that single-use biosensors, which cannot be rapidly and reproducibly regenerated, should be designated as such. They also highlight the need for rigorous definitions and classification of biosensors to address the rapid proliferation and diversity of these devices.The article "Electrochemical Biosensors: Recommended Definitions and Classification" by Daniel R. Thevenot, Klara Toth, Richard Durst, and George S. Wilson provides a comprehensive overview of electrochemical biosensors, including their definitions, classifications, and performance criteria. The authors define an electrochemical biosensor as a self-contained integrated device that uses a biological recognition element (biochemical receptor) in direct spatial contact with an electrochemical transducer to provide specific quantitative or semi-quantitative analytical information. They distinguish electrochemical biosensors from bioanalytical systems, which require additional processing steps such as reagent addition. The classification of biosensors is based on the biological specificity-conferring mechanism or the mode of physicochemical signal transduction. The biological recognition element can be based on biocatalytic reactions or biocomplexing interactions. The transduction modes include amperometry, potentiometry, surface charge using field-effect transistors (FETs), and conductometry. The article also discusses the direct and indirect monitoring of analytes or reactions, the construction of biosensors, and performance criteria such as calibration characteristics, selectivity, response times, sample throughput, reproducibility, stability, and lifetime. It emphasizes the importance of standard protocols for evaluating these criteria and provides guidelines for reporting the characteristics of biosensor responses. The authors recommend that the term "biosensor" should be clearly distinguished from "bioanalytical system" and that single-use biosensors, which cannot be rapidly and reproducibly regenerated, should be designated as such. They also highlight the need for rigorous definitions and classification of biosensors to address the rapid proliferation and diversity of these devices.