On-site marine pathogen (Vibrio parahaemolyticus) rapid colorimetric determination based on modified-free aptamer and metal-organic frameworks with simple washing step

Nowadays, microbial visual sensing platforms based on aptamers and metal-organic frameworks (MOFs) have been reported, but most of them require complex modification processes, which undoubtedly increases the difficulty of detection. Here, we constructed modified-free magnetic-aptamer MOF (Fe 3 O 4 -Ap@ZIF-8) and signal-aptamer MOF (Pt-Ap@ZIF-8), which effectively avoided complex biological modification. The rapid sensing strategy was adopted in this method to avoid the complicated washing steps and greatly shorten the detection time. The performance of this method was verified by taking Vibrio parahaemolyticus (VP) as the mode target. The limit of detection (LOD) of VP is 10 2 CFU/mL. Furthermore, this strategy can achieve rapid visual analysis of other target objects only by changing different aptamers, and has broad application prospects in the fields of rapid detection of food pollutants, rapid medical diagnosis, environmental monitoring, etc. • The metal nanoparticles-aptamer@ZIF-8 complex without modification was synthesized by biomimetic mineralization. • The on-site biosensing strategy based on the dual MOF complex reduces the difficulty and cost of MOF anchored bio-probe. • The rapid one-step sensing strategy eliminates the need for multiple washing processes, greatly reducing the test time. • This method can reduce the cost of analysis and has good universality for other targets only by changing aptamers.