Shellfish farming in aquaculture faces significant challenges due to global warming. During their growth process, shellfish filter large volumes of water, which can lead to the accumulation of toxins within their bodies. Consuming toxin-contaminated shellfish can cause serious health issues in humans. The aim of this project is to develop a rapid in situ test capable of detecting multiple toxins simultaneously, based on aptamer technology—single-stranded oligonucleotides that specifically bind to various toxins. Its ease of use and cost-effectiveness will enable widespread application in aquaculture and contribute to safer consumption of shellfish products.