Advancements of the Vibrio coralliilyticus eDNA detection based on Co-Fe PBA-assisted biosensors for the rapid coral-disease warning

Abstract

Vibrio coralliilyticus (V. coralliilyticus) can lead to severe coral diseases and is one of the main causes of coral bleaching. However, there is still a lack of convenient, and non-invasive detection methods for V. coralliilyticus, which brings inconvenience to coral health management. Here, a portable electrochemical biosensor was developed based on environmental DNA (eDNA) and cobalt-iron Prussian Blue Analogue (Co-Fe PBA) electrode material for detecting V. coralliilyticus. Notably, this sensor identified and quantified V. coralliilyticus eDNA in water through specific DNA probes, overcoming the previously reported complex and destructive pretreatment processes. Additionally, thanks to the high specific surface area of Co-Fe PBA, which provided abundant sites for probe anchoring, the constructed portable biosensor exhibited excellent detection performances. Specifically, the detection limit was as low as 19.0 fM, and the linear range was from 100 fM to 100 nM. In subsequent coral infection experiments, the eDNA of V. coralliilyticus increased on the eve of coral bleaching. Based on this change, the occurrence of coral bleaching was successfully predicted. Therefore, this portable biosensor is suitable for dynamic monitoring of V. coralliilyticus, helping to reveal the potential risks to coral health and providing a reference for ecological decision-making for coral reef protection.