Nb.BbvCI powered DNA walking machine-based Zr-MOFs-labeled electrochemical aptasensor using Pt@AuNRs/Fe-MOFs/PEI-rGO as electrode modification material for patulin detection

A Nb.BbvCI powered DNA walking machine as signal enhancer, gold-platinum core-shell nanorods/iron-based metal-organic frameworks/polyethyleneimine-reduced graphene oxide composites ([email protected]/Fe-MOFs/PEI-rGO) as electrode modification material and Zr-based metal-organic frameworks-labeled oligonucleotides load with methylene blue ([email protected]) as signal probes has been fabricated to obtain a sensitive electrochemical aptasensor for patulin (PAT) detection. In the DNA walking machine, PAT takes the aptamer away from the DNA walking chain (wDNA), and wDNA can repeatedly dissociate the [email protected] under the Nb.BbvCI power to amplify the detection signal. In addition, [email protected]/Fe-MOFs/PEI-rGO modified gold electrode provides high stability (60 scans without significant change), catalytic performance (compared to bare gold electrode signal enhancement 250%), and high conductivity (calculated apparent electron transfer rate constant is 1.64 s−1). With such design, the as- prepared aptasensor exhibits good sensitivity from 5.0 × 10−5 ng·mL−1 to 5.0 × 10−1 ng·mL−1 with a detection limit of 4.14 × 10−5 ng·mL−1. This aptasensor construction mode can supply one efficient approach to improve signal amplification, which also open an avenue for sensitivity enhancement in detection of analytes.