Optimization of an OLED-based immunosensor for the detection of tetrodotoxin in mussels

Alien species have colonized new aquatic ecosystems due to multifactorial effects, among which climate change or the increasing of the marine traffic, can be mentioned. The occurrence of contamination due to tetrodotoxin (TTX) is now observed in the Mediterranean Sea and in bivalves, whereas TTX was classically contaminating pufferfish in the Pacific Ocean. In this paper, we present the optimization of an Organic Light Emitting Diode (OLED) based immunosensor to detect tetrodotoxin in spiked samples of mussels. An ELISA test was preliminary optimized to set the concentrations of all biological elements required to develop the OLED-immunoaffinity-based biosensor and to mutually validate the two detection systems presently optimised. The threshold concentration of 44 ng g−1 set by EFSA for TTX in seafood products was used to distinguish the negative mussel samples from the positive ones. A streamlined extraction protocol was adopted after its optimization to fulfil the need of the assay (European food safety authority, 2017).