A 'signal-on' voltammetric aptasensor fabricated by hcPt@AuNFs/PEI-rGO and Fe_3O_4NRs/rGO for the detection of zearalenone

摘要

A "signal-on" electrochemical aptasensor was proposed by employing hollow cubic platinum@gold nanoframes functionalized polyethyleneimine-reduced graphene oxide (hcPt@AuNFs/PEI-rGO) as the label material and Fe3O4 nanorods/reduced graphene oxide (Fe(3)O(4)NRs/rGO) for quantitative detection of zearalenone (ZEN). In this work, the hcPt@AuNFs/PEI-rGO with excellent conductivity and large surface area was synthesized as the label material, which can increase the loading of Thi and DNA S1. The Fe(3)O(4)NRs/rGO as the platform was decorated on gold electrodes, which can not only effectively improve the load capacity of the gold nanoparticles (AuNPs) and the DNA S2 but also catalyze Thi, thereby improving analytical performance of the aptasensor. Upon the specific recognition of aptamers to ZEN, the remained DNA S2 captured the hcPt@AuNFs/PEI-rGO immobilized with DNA S1 by hybridization reaction. With the aid of signal amplification system (hcPt@AuNFs/PEI-rGO and Fe(3)O(4)NRs/rGO), the aptasensor exhibited a linear relationship related to the logarithmic values of ZEN concentration from 0.5 pg/mL to 50 ng/mL with a low detection limit of 0.105 pg/mL under optimal conditions. Meanwhile, the aptasensor exhibited satisfactory specificity, good stability, excellent reproducibility and provided a potential application in maize samples.