Key Points
- A novel, cost-effective fluorescence polarization (FP) assay using bovine serum albumin nanoparticles (BSA NPs) and manganese dioxide nanosheets (MnO₂ NS) to detect common food additives without the need for expensive antibodies or aptamers.
- The assay leverages the oxidative behavior of MnO₂ and the production of hydrogen peroxide (H₂O₂) during enzymatic reactions with the food additives' respective oxidases, resulting in a measurable FP signal change.
- Validated on real beverage samples (milk, Sprite, soybean milk, white wine), the method showed high accuracy and consistency with commercial kits.
In a recent study, a team of researchers from Guangdong Medical University examined a new method that can improve the detection and quantification of food additives. This study, which was published in the journal Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, presents a new fluorescence polarization (FP) assay that can accomplish this (1).
What are food additives, and what are some of the common ones?
Food additives are chemicals designed to perform a specific function. Normally, food additives are used to increase the shelf life of the food product or improve its color, flavor, and texture (2). Although food additives are important to the food industry, their regulation is closely monitored for health and safety reasons. Some of the most common food additives include glucose, choline, and lactate (1).
What was the FP assay that the researchers created?
Traditional FP assays often depend on the use of fluorescently labeled antibodies or aptamers to target specific analytes. These components are not only expensive and complex to produce, but they also introduce challenges such as limited shelf life, signal interference, and the requirement for precise storage conditions (1).
The assay developed in this study looked to overcome these challenges. In their study, the researchers created their assay by using bovine serum albumin nanoparticles (BSA NPs) combined with manganese dioxide nanosheets (MnO₂ NS) to create a robust, sensitive, and cost-effective sensing platform (1).
One of the important aspects of this newly created FP assay was the synergistic interaction between BSA NPs and MnO₂ nanosheets. Although the BSA NPs alone produce a weak FP signal, the addition of MnO₂ nanosheets significantly amplifies this signal (1). However, the key to detection lies in the oxidative behavior of MnO₂ (1). When hydrogen peroxide (H₂O₂) is introduced, it disrupts the MnO₂-enhanced FP signal, leading to a measurable decrease.
Some of the most common food additives, which include glucose, sodium lactate, and choline, generate H₂O₂ when metabolized by their respective oxidases (glucose oxidase, choline oxidase, and lactate oxidase) (1). By coupling these enzymatic reactions with the FP response of the BSA NPs-MnO₂ NS system, the researchers were able to develop a sensitive platform capable of detecting these additives within relevant concentration ranges: 0–200 μM for glucose and lactate, and 0–800 μM for choline (1).
How did the team validate their method?
To test their method, the researchers selected beverages that contain food additives. For the validation process, milk, Sprite, soybean milk, and white wine were used. The researchers found that for the milk samples, the recoveries for glucose, choline, and lactate ranged from 98.5% to 106.8%, 90.1% to 107.6%, and 104.6% to 105.3%, respectively, with the relative standard deviations (RSDs) below 4.7% (1). These results demonstrate both high accuracy and reproducibility.
For Sprite, the FP assay results closely aligned with those obtained from a commercial assay kit, with recoveries between 97.6% and 99.7% (1). Similarly, choline detection in soybean milk yielded results ranging from 93.4% to 106.4%, and lactate detection in white wine showed recoveries between 102.2% and 109.8%, which were all in agreement with traditional commercial assays (1).
What are the key takeaways from this study?
The results obtained from this study indicate that the label-free FP assay developed by the researchers can be applied in more industries apart from food analysis, such as biochemical research and medical diagnostics. Since the detection relies on the production of H₂O₂, any analyte that can be oxidized to generate H₂O₂ through enzyme catalysis could potentially be measured using this system (1). The assay also requires no complex labeling procedures, no specialized reagents like antibodies or aptamers, and no sophisticated detection equipment beyond standard fluorescence instrumentation. This makes this assay more accessible for those laboratories and researchers who don’t have the money to buy expensive instrumentation.
By offering a rapid, low-cost, and reliable alternative to conventional assays, this study highlights an ongoing trend of developing new point-of-care diagnostic tools and in-field testing kits (1). With growing concerns around food safety, consumer health, and the need for decentralized analysis methods, this technology arrives at an opportune moment.
Through the use of BSA nanoparticles and MnO₂ nanosheets, the research at Guangdong Medical University has created a promising, label-free assay platform that combines simplicity with precision, which has potential to be more widely used to monitor food additives in common food products consumers purchase.
References
- Fan, S.; Wang, J.; Wen, X.; et al. A Label-free Fluorescence Polarization Technology for the Detection of Food Additives. Spectrochimica Acta Part A: Mol. Biomol. Spectrosc. 2026, 344 Part 1, 126634. DOI: 10.1016/j.saa.2025.126634
- Victoria State Government, Food Additives. Better Health Channel. Available at: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/food-additives (accessed 2025-07-18).
