Enhanced stability of CH₃NH₃PbBr₃ quantum dots for electrochemiluminescence detection of saxitoxin

Saxitoxin (STX) is a highly potent phycotoxin that poses a severe threat to both human health and aquatic ecosystems. Given its extremely low permissible level in food products, there is an urgent need for a sensitive, specific, and cost-effective screening method. In this study, an electrochemiluminescence (ECL)-based method was developed for STX detection, capitalizing on the inherent advantages of ECL, including high sensitivity and minimal background interference. To achieve selective recognition of STX, molecularly imprinted polymers (MIPs) featuring specific memory cavities were modified onto MAPB QDs@SiO₂. Benefiting from the label-free nature of MIPs and the unique electronic properties of MAPB QDs, the fabricated ECL sensor exhibited excellent sensitivity with a low detection limit of 1.2 fg/mL and high selectivity against other biotoxins. With its simplicity, outstanding sensitivity, and reliable specificity, this sensor represents a promising tool for STX monitoring in environmental and food safety applications.