Rapid assessment of bisphenol A toxicity on fish eggs using optical nanomotion detection

Fish have a vital role in environment and human nutrition worldwide. Assessing the health of fish reproductive cells is crucial for both wild populations and aquaculture, serving as a key indicator of ecosystem health and the safety of seafood. Bisphenol A (BPA), a plastic monomer, emerges as an environmental pollutant with toxic effects on aquatic organisms, particularly disrupting reproduction. Traditional biomarkers for sperm and egg quality can be complex and resource-intensive, prompting the need for simpler, rapid testing methods. This study utilizes a nanomotion-based technique to assess the viability of carp (Cyprinus carpio) eggs exposed to BPA. Nanomotion measures cell oscillations, which cease on viability loss. Unfertilized and fertilized carp eggs were exposed to varying BPA concentrations, and x-y motions were recorded. Statistical analyses showed significant changes in unfertilized and fertilized egg nanomotion on BPA exposure, indicating increased cell activity in contaminated samples. The second-order polynomial model characterizes the dose-response of cellular nanomotion to increasing BPA concentrations. The estimation indicates that maximum nanomotion occurs at a BPA concentration of 0.03 mM in both unfertilized and fertilized eggs. According to our knowledge, this study reports for the first time use of an optical nanomotion method for direct assessment of the effect of a pollutant on fish eggs. This method showed that both unfertilized and fertilized eggs are sensitive to BPA exposure. By mimicking natural fertilization conditions, it deepens our understanding of aquatic ecosystems and helps to protect fisheries and global food security. This method offers a simple, rapid, and effective tool for assessing the impact of environmental contaminants on fish reproductive health.