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 (Pt@AuNRs/Fe-MOFs/PEIrGO) as electrode modification material and Zr-based metal-organic frameworks-labeled oligonucleotides load with methylene blue (MB@Zr-MOFs-cDNA) 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 MB@Zr-MOFs-cDNA under the Nb.BbvCI power to amplify the detection signal. In addition, Pt@AuNRs/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 asprepared aptasensor exhibits good sensitivity from 5.0 x 10(-5) ng.mL(-1) to 5.0 x 10(-1) ng.mL(-1) with a detection limit of 4.14 x 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.

Automated summary

A sensitive electrochemical aptasensor for patulin detection was developed by using a DNA walking machine as signal enhancer, composite electrode modification material, and Zr-based metal-organic frameworks-labeled oligonucleotides as signal probes. The designed aptasensor showed good sensitivity and signal amplification capabilities, providing a promising approach for improving analyte detection sensitivity.