New Low-Cost Fluorescent Probe Offers Rapid Detection of Toxic Hydrazine in the Environment and Food

Chemical sensing technology is being developed at a rapid pace in an effort to solve some of the most pressing food safety and environmental challenges. A recent study conducted by researchers at Jiangnan University tested a newly developed near-infrared (NIR) fluorescent probe that could detect hydrazine with improved sensitivity and selectivity. This study, which was published in the journal Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, was led by Wen-Long Wang of Jiangnan University in China. The fluorescent probe, proprietary named as MCM-OMe, introduced in this study, was designed to be low-cost and easy to manufacture, which makes it useful to assess hydrazine contamination.

Oil bubbles tinted with fluorescent dyes, glowing brightly under ultraviolet light, creating a surreal and psychedelic visual experience. Generated with AI. | Image Credit: © MAY - stock.adobe.com.

What is Hydrazine?

Hydrazine (N₂H₄) is a highly toxic and potentially carcinogenic compound. It is a molecule that has two single-bonded nitrogen atoms and four hydrogen atoms (2). Hydrazine is commonly used to make foaming agents such as azodicarbonamide, and it is used in various industrial applications, including rocket fuels, pharmaceuticals, and agricultural chemicals like pesticides (1,2). Because of its volatility and toxicity, even trace amounts of residual hydrazine in water, soil, or food can pose significant health and ecological risks.

What Does the MCM-OMe Probe Do That Traditional Detection Methods Don’t?

The problem with existing detecting methods is that they are expensive and complex. Because of these two factors, many laboratories and scientists cannot conduct the necessary investigations in a timely manner. The MCM-OMe fluorescent probe that Wang’s team developed and tested was designed to mitigate these issues, presenting a cheaper alternative for hydrazine detection (1).

MCM-OMe is a derivative of a 2H-chromene scaffold integrated with a dicyanovinyl (DCV) group (1). This molecular structure enables the probe to undergo a nucleophilic substitution reaction specifically with hydrazine, triggering a measurable change in its fluorescence profile and solution color (1). The authors explain that this color change is detectable by the naked eye and easily monitored via fluorescence spectroscopy (1).

What Was Wang and Team’s Experimental Procedure?

Wang and colleagues designed and synthesized three derivatives, MCM-H, MCM-Cl, and MCM-OMe, to evaluate their relative efficacy in hydrazine detection. Among the three, MCM-OMe, which contains electron-donating methoxy groups, exhibited the most favorable performance, demonstrating the strongest ratiometric fluorescent response (1). According to the study, the probe showed not only high sensitivity and selectivity but also impressive acid-base tolerance, allowing it to maintain its performance across varied environmental conditions (1).

Then, the researchers ran their probe through a series of tests to help determine whether it can be applied in real-world applications. To conduct these tests, the researchers took soil samples from the loess and mudflat regions near Taihu Lake, as well as food samples such as turnip, water celery, and shrimp. Using the MCM-OMe probe to analyze them, the researchers found that their probe could reliably detect trace levels of hydrazine (1). Notably, the probe's detection limit was significantly below the U.S. Environmental Protection Agency's (EPA) guideline threshold for hydrazine exposure, highlighting its suitability for regulatory compliance and public health monitoring (1).

What Are The Key Takeaways From This Study?

An important takeaway from this study is that apart from testing the efficacy of the MCM-OMe probe for its ability to detect hydrazine, the team also developed prototype applications of the probe in the form of portable test strips and even hydrazine-sensitive laboratory coats. These wearable sensors fluoresce in response to hydrazine vapors, providing immediate visual feedback to laboratory personnel or environmental workers exposed to the chemical (1). As a result, these innovations could help improve workplace safety practices in industries handling hazardous substances (1).

As future studies can refine the MCM-OMe fluorescent probe, the researchers also hope that their probe can be integrated in commercial hydrazine testing kits, environmental monitoring stations, and quality control pipelines in the food industry (1). The findings of this study show that fluorescent molecular probes continue to be effective tools to assess industrial pollutants in the environment and food.

References

1. Dong, F.; Zhang, C.; Fu, Y.; Wang, W.-L. Novel near-infrared 2H-chromene-based ratiometric fluorescent probe: Rapidly monitoring hydrazine in real samples. Spectrochimica Acta Part A: Mol. Biomol. Spectrosc. 2025, 340, 126225. DOI: 10.1016/j.saa.2025.126255
2. Fletcher-Wood, R. Hydrazine. Education in Chemistry. Available at: https://edu.rsc.org/magnificent-molecules/hydrazine/2000023.article (accessed 2025-05-13).