Researchers at the Shiv Nadar Institution of Eminence in Delhi-NCR have developed a new and cost-effective sensor that can detect toxic chemicals such as formalin in food samples like preserved meat, fish, and honey. The chemical sensor, described in the journal ChemComm, provides good sensing ability to formaldehyde or formalin, a naturally occurring organic compound, up to 0.3 micro Moles (‘M).
According to the Food Safety and Standards of India (FSSAI) regulation 2011, formalin is not permitted for use in food. However, it is often used as a preservative for fish and meat and as a disinfectant for treating external parasites and fungi in aquaculture. The sensor developed by the research team can detect formaldehyde in real samples, including preserved fish and chicken, and can also quantify other analogues in honey such as methyl glyoxal (MGO). The detection method uses a simple optical method, specifically fluorescence, to detect formaldehyde. Low concentrations can be detected using a fluorimeter, while higher concentrations can be detected by the naked eye using a simple UV torch. This method is easy and inexpensive for real sample analysis, including preserved fish and honey.
Current fluorescent-based small molecular sensors for formaldehyde are either partially or not soluble in an aqueous solution, limiting their real application in preserved food samples. In contrast, the new sensor developed by the research team is highly water-soluble and can be used for simultaneous detection and discrimination among formaldehyde and other analogues such as MGO.
The research team is now working on developing a test kit that can be detected by a mobile device onsite, rather than using a spectrophotometer. This research is a proof-of-concept and a practical demonstration of analyzing toxic pollutants in food samples.