In a recent article published in the journal Proceedings, researchers presented a novel approach utilizing a smart sensor based on square wave anodic stripping voltammetry (SWASV) for the rapid and cost-effective determination of mercury during food analysis.
Study: Smart Sensor for Mercury Detection in Novel Food. Image Credit: Francesco Scatena/Shutterstock.com
Background
Mercury contamination in aquatic ecosystems arises from both natural and anthropogenic sources, leading to its bioaccumulation in various organisms. Mercury (Hg(II)), a well-known toxic contaminant, poses significant health risks due to its accumulation in the human body through the food chain. Exposure to even low levels of mercury can lead to severe health issues, including neurological damage and adverse effects on fetal development.
The increasing concern over food safety has prompted the development of advanced food analysis techniques for detecting hazardous substances in food products. Traditional methods for mercury analysis often involve complex procedures and expensive equipment, which can limit their applicability in routine food safety assessments.
This study aimed to address these challenges by developing a smart sensor that combines the advantages of nanocomposite materials and portable electrochemical techniques. The sensor employs screen-printed graphite electrodes modified with poly(L-aspartic acid) and gold nanoparticles, enhancing the electrochemical response for mercury detection.
The Current Study
The research involved the fabrication of nanocomposite screen-printed graphite electrodes (GSPEs) through a two-step modification process. Initially, poly(L-aspartic acid) was electrodeposited onto the graphite working electrodes using cyclic voltammetry (CV). This was followed by the deposition of gold nanoparticles (AuNPs) using chronoamperometry. The modified electrodes were characterized using electrochemical techniques, including cyclic voltammetry and electrochemical impedance spectroscopy, to assess their performance in detecting mercury.
The analytical performance of the developed sensor was evaluated through SWASV, which allows for the sensitive detection of trace levels of mercury. Key experimental parameters, such as deposition time and potential, were optimized to achieve the best analytical response.
The calibration curves were established in both beaker and drop configurations, demonstrating a wide dynamic range for mercury detection. The sensor's limit of detection was determined to be 0.25 μg/L, indicating its suitability for analyzing low concentrations of mercury in food samples.
Results and Discussion
The results of the study demonstrated that the optimized AuNPs@p(L-Asp)/GSPEs exhibited excellent electrochemical performance for mercury detection. The calibration curves obtained showed a dynamic range of 1–60 μg/L in drop configuration and 1–100 μg/L in beaker configuration, with corresponding limits of detection of 0.25 μg/L and 0.28 μg/L, respectively. These findings highlight the sensor's capability to detect mercury at trace levels, which is crucial for food safety applications.
The developed sensor was applied to analyze real food samples, specifically cricket flour and seaweed. Prior to analysis, the samples underwent mineralization using a microwave oven, following standard procedures for mercury analysis. The results obtained from the smart sensor were compared with those from a reference method, demonstrating the reliability and accuracy of the proposed approach. The integration of the sensor with a portable potentiostat connected to a smartphone facilitated on-site analysis, making it a practical tool for food safety monitoring.
The study also discussed the advantages of using nanocomposite materials in sensor development for food analysis. The combination of poly(L-aspartic acid) and gold nanoparticles significantly enhanced the electrochemical response, leading to improved sensitivity and selectivity for mercury detection. The use of screen-printed electrodes further contributed to the sensor's cost-effectiveness and ease of use, making it suitable for widespread application in food safety assessments.
Conclusion
In conclusion, this research presents a significant advancement in the field of food safety through the development of a smart sensor for mercury detection in food analysis. Square wave anodic stripping voltammetry at nanocomposite screen-printed graphite electrodes offers a simple, fast, and cost-effective method for analyzing trace levels of mercury in food samples. The sensor's high sensitivity, wide dynamic range, and portability make it an ideal tool for on-site monitoring of food safety.
As mercury contamination remains a critical public health concern, this study's findings underscore the importance of developing reliable analytical techniques to ensure the safety of food products. Future work may focus on further optimizing the sensor's performance and expanding its application to a broader range of food matrices, ultimately contributing to enhanced food safety and public health protection.
Journal Reference
Vitale I.A., Selvolini G., et al. (2024). Smart Sensor for Mercury Detection in Novel Food. Proceedings, 97, 232. DOI: 10.3390/proceedings2024097232, https://www.mdpi.com/2504-3900/97/1/232