A Decade of Innovation in Hydrazine Detection Methods

Hydrazine is an extremely toxic and carcinogenic compound extensively applied in industry, which prompts the development of sensitive and reliable sensors for environmental and biological monitoring. While traditional techniques such as chromatography and spectrophotometry offer high sensitivity, their reliance on complex instrumentation and a lengthy sample preparation procedure limits their field applicability. The development of spectroscopy, electrochemistry and nanomaterial-based sensors in recent years has greatly improved hydrazine detection with high sensitivity, selectivity and real-time monitoring. For example, fluorescence spectroscopy can detect at levels as low as 1.5 ppb using reaction based and material-based probes, while colorimetric and surface enhanced Raman spectroscopy (SERS) provide rapid and cost-effective on-site analysis. Electrochemical sensors, incorporating nanomaterials and conducting polymers, allow portable and low-cost monitoring with sub-nanomolar limit of detection (LOD). New techniques including microfluidics, photoelectrochemical (PEC) sensors, and optical fiber-based systems further enhance field deployability and multifunctional sensing capabilities. However, in spite of these advancements, challenges remain in long-term sensor stability, interference resistance, and commercialization. Current hydrazine detection technologies are thoroughly reviewed, emphasizing significant research gaps. Future directions emphasize hybrid sensing, machine learning, and sustainable nanomaterials to connect laboratory research with practical applications. By addressing these challenges, next-generation sensors can greatly enhance environmental monitoring, industrial safety, and public health protection.