Inspired by the modulatable nanozymatic activity of covalent organic frameworks (COFs) by single-stranded DNA (ssDNA), herein, we developed a versatile platform for sensitive/specific colorimetric detection and efficient adsorption of UO22+ based on DNA aptamer-functionalized COFs. Three COFs with varying alkyne contents (Py-BDA, Py-BDA-BPTA, and Py-BPTA) were synthesized, followed by precisely covalent immobilization of UO22+-specific DNA aptamers via click chemistry. These COFs possess intrinsic oxidase-mimicking activity capable of catalyzing TMB oxidation to oxTMB, and the DNA aptamer covalent modification can regulate the enzymatic activity of COFs, with the most suppressing effect for Py-BDA-BPTA. The subsequent UO22+ binding can significantly restore the nanozymatic activity of Py-BDA-BPTA by charge neutralization. This "off-on" switching mechanism enabled sensitive and selective UO22+ detection with a low limit of detection (LOD) about 10 nM (3σ). Moreover, the DNA aptamer-functionalized COFs can be applied for efficient adsorption and removal of UO22+ with rapid kinetics and excellent cycling stability. This study provides novel insights into the postmodification of COFs by biomacromolecules to modulate their mimic enzymatic activity for sensing and adsorption applications.
While nanozyme-based inhibition strategies are attractive for on-site detection of pesticides, their sensitivity is primarily hampered by insufficient interactions at the nanozyme-pesticide interface. To address this, we developed a dual-recognition system that integrates a Fe/Cu-N-C single-atom nanozyme (SAzyme) with...
Li-Jun Wang, Kun-Rong Zhao, Ming-Hui Luo et al.· Food Chemistry· 0 citations
Developing highly sensitive and stable electrochemiluminescence (ECL) biosensing platforms requires overcoming inherent limitations, such as aggregation-caused quenching (ACQ) of luminophores and coreactant-induced electrode passivation. In this work, we developed an ECL biosensor capable of detecting microcystin-LR...
A bipyridine-functionalized covalent organic polymer (Bpy-COP) was synthesized as a fluorescent sensor for Zn2+ detection in pure water. Structural characterization confirmed the formation of an imine-linked amorphous polymer incorporating accessible bipyridine coordination sites within a conjugated framework. Upon Zn2...
Herein, an electrochemiluminescent (ECL) aptasensor based on porphyrin-based covalent organic framework (TP-COF) was constructed for the ultrasensitive detection of kanamycin (KANA). The ordered porous channels and porphyrin-centered π-conjugated framework of TP-COF optimize the interfacial microenvironment and acceler...
Zi-Han Fang, Fu-Ge Chai, Jing-Yi Xu et al.· Talanta: The International J...· 0 citations
A novel Hg2+ sensing strategy has been developed based on a Mn-Au hybrid nanozyme with prominent oxidase-like activity and an aptamer-controlled catalytic switching mechanism. First, a Mn-Au hybrid nanozyme (MnAuNPs) with a distinctive “fried-egg-like” core–shell morphology was synthesized, which exhibited remarkable o...
Chen Ma, Yi-Da Zhang, Shuai Mu et al.· Microchimica Acta· 0 citations
Existing colorimetric sensing strategies based on gold nanoparticles (AuNPs) are largely limited to the detection of free metal ions, leaving metal–organic complexes widely present in real water bodies undetectable. Herein, we develop a simple colorimetric method based on the anti-aggregation effect of bare AuNPs for t...
