Achieving precise monitoring of hazardous gases, toxic chemicals, and characteristic biomolecules through facile and efficient means is of paramount importance for safeguarding global environmental security and human health. As an emerging class of two-dimensional materials, MXenes not only exhibit outstanding physical properties but also allow for precise optimization of their chemical, optical and electronic characteristics through the modulation of surface terminal groups. This review (DOI: 10.1002/elt2.70028) establishes a comprehensive knowledge framework encompassing material preparation, performance analysis, mechanistic studies, and practical biochemical sensing applications, aiming to fill the existing literature gap in this domain.