Fenton-like catalytic MOFs driving electrochemical aptasensing toward tracking lead pollution in pomegranate fruit

Abstract

Pomegranate is very favored but highly susceptible to lead contamination that threatens consumer health, and thereby it is essential to establish efficient modes to monitor lead level in pomegranate. A specific and sensitive electrochemical sensor was developed for assessing lead pollution in pomegranate based on Pb²⁺-dependent DNAzyme as recognition receptor and metal-organic frameworks (MOFs) for signal output. Particularly, the used MOFs exhibited Fenton-like catalytic functions toward methylene blue (MB) as electroactive medium. Integrating with gold nanoparticles (AuNPs), the Fenton-like MOFs showed high sensitivity for electrochemical detection of Pb²⁺ in pomegranate. Moreover, benefiting from the specific recognition of DNAzyme to Pb²⁺, the adjustable strategy was achieved, in which the approaching MB led to a higher signal with the absence of Pb²⁺ while the detached MB gave rise to a lower signal with the presence of Pb²⁺. With the use of Fenton-like catalytic MOFs driving electrochemical aptasensing interface, this simplified detection pattern was endowed with sensitive assessment of lead pollution level in pomegranate, highlighting its promising potential in evaluating the safety of foodstuffs.