Faraday cage-type aptasensor for dual-mode detection of Vibrio parahaemolyticus

A Faraday cage-type aptasensor has been developed for dual-mode detection of a common bacterial pathogen Vibrio parahaemolyticus (VP) by electrochemiluminescence (ECL) and differential pulse voltammetry (DPV), using a multi-functionalized material Pb²⁺-Ru-MOF@Apt2 as signal unit. The recognition aptamer Apt2 recognizes VP; specifically, ruthenium-based metal organic framework (Ru-MOF) and lead ions (Pb²⁺) embedded produce an ECL signal at a working potential from 0 to 1.5 V and DPV signal from − 0.3 to − 0.8 V vs. Ag/AgCl. Since Ru-MOF is a two-dimensional conductive material signal unit overlapped onto the electrode surface to form a Faraday cage-type aptasensor. Thus, electrons could be easily exchanged between electrode and signal tags without being hindered by micron-size VP, resulting in a high detection sensitivity with a detection limit of 1.7 CFU mL⁻¹. In addition, dual-mode detection was achieved, improving the accuracy and reliability of rapid field detection. Stability and selectivity were also satisfactory. The tests of real samples indicate that this Faraday cage-type aptasensor is suited for rapid detection of VP and analog pathogens and shows great potential in food safety.