This study addresses the need for rapid pesticide (acetamiprid) detection by reporting a new colorimetric biosensing assay. Our approach combines the inherent peroxidase-like nanozyme activity of gold nanoparticles (GNPs) with high affinity and specificity of an acetamiprid-specific S-18 aptamer to detect this neurotoxic pesticide in a highly rapid, specific, and sensitive manner. It is shown that the nanozyme activity of GNPs can be inhibited by its surface passivation with target-specific aptamer molecules. Similar to an enzymatic competitive inhibition process, in the presence of a cognate target, these aptamer molecules leave the GNP surface in a target concentration-dependent manner, reactivating GNP nanozyme activity. This reversible inhibition of the GNP nanozyme activity can either be directly visualized in the form of color change of the peroxidase reaction product or can be quantified using UV-visible absorbance spectroscopy. This approach allowed detection of 0.1 ppm acetamiprid within an assay time of 10 min. This reversible nanozyme activation/inhibition strategy may in principle be universally applicable for the detection of a range of environmental or biomedical molecules of interest.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ac5028726 | DOI Listing |
Mikrochim Acta
December 2024
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China.
A novel copper and iron doped containing chitosan and heparin sodium carbon dots (CS-Cu,Fe/HS) nanozyme was formulated through a single-step microwave digestion method. CS-Cu,Fe/HS exhibits excellent peroxidase (POD)-like activity and positive charge characteristics, and it can oxidize the negatively charged 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in the presence of HO to produce a green compound (ox-ABTS). Furthermore, CS-Cu,Fe/HS enhances electron transfer and provides additional active sites through the valence state transformations of Fe/Fe and Cu/Cu.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Center for Genomics and Precision Medicine, Institute of Bioscience and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA.
Our group has synthesized a pleiotropic synthetic nanozyme redox mediator we term a "pleozyme" that displays multiple enzymatic characteristics, including acting as a superoxide dismutase mimetic, oxidizing NADH to NAD, and oxidizing HS to polysulfides and thiosulfate. Benefits have been seen in acute and chronic neurological disease models. The molecule is sourced from coconut-derived activated charcoal that has undergone harsh oxidization with fuming nitric acid, which alters the structure and chemical characteristics, yielding 3-8 nm discs with broad redox potential.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Center for Genomics and Precision Medicine, Institute of Bioscience and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA.
Harsh acid oxidation of activated charcoal transforms an insoluble carbon-rich source into water-soluble, disc structures of graphene decorated with multiple oxygen-containing functionalities. We term these pleiotropic nano-enzymes as "pleozymes". A broad redox potential spans many crucial redox reactions including the oxidation of hydrogen sulfide (HS) to polysulfides and thiosulfate, dismutation of the superoxide radical (O*), and oxidation of NADH to NAD.
View Article and Find Full Text PDFBiosensors (Basel)
November 2024
Department of BioNano Technology, Gachon University, 1342 Seongnamdae-ro, Sujeong-gu, Seongnam 13120, Republic of Korea.
Choline is an important molecule in monitoring food safety and infant nutrition. Here, we report Ce nanogels synthesized by atom transfer radical polymerization (ATRP) employing Ce-coordinated acryloyl-lysine polymer brushes (Ce@SiO NGs) as highly efficient cascade nanozymes for colorimetric detection of choline. The synthesized Ce@SiO NGs demonstrated remarkable peroxidase-like activity with a porous exterior, which are essential to entrap choline oxidase (COx) to yield COx@Ce@SiO NGs and construct a cascade reaction system to detect choline.
View Article and Find Full Text PDFTalanta
December 2024
Chongqing Key Laboratory of Conservation and Utilization of Freshwater Fishes, Animal Biology Key Laboratory of Chongqing Education Commission of China, Chongqing Normal University, College of Life Sciences, Chongqing, 401331, China. Electronic address:
Nanozymes, characterized by enzyme-like activity, have been extensively used in quantitative analysis and rapid detection due to their small size, batch fabrication, and ease of modification. Researchers have combined aptamers, an emerging molecular probe, with nanozymes for biosensing to address the limited reaction specificity of nanozymes. Nanozyme aptasensors are currently experiencing significant growth, offering a promising solution to the lack of rapid detection methods across various fields.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!