The Asian tiger mosquito Aedes albopictus transmits several arboviruses, including chikungunya, Zika, and dengue, posing serious public health threats. The excessive use of insecticides has led to increasing resistance to commonly applied insecticides in this species. We previously observed that enhanced expression of a CYP6Z8 homolog (AalbCYP6Z8) was associated with insecticide resistance in two field populations of Ae. albopictus ; however, its capacity in insecticide metabolism had not been biochemically characterized. In this study, to explore the potential role of AalbCYP6Z8 in insecticide metabolism, a fully functional enzyme system was reconstituted in vitro by using Escherichia coli –produced recombinant AalbCYP6Z8 and NADPH-dependent cytochrome P450 reductase along with cytochrome b 5. Our metabolism assays showed that CYP6Z8 was capable of metabolizing organophosphates (temephos and malathion) and carbamates (propoxur and bendiocarb), but not pyrethroids (deltamethrin and permethrin). Mass spectrometry analyses tentatively identified the structures of specific metabolites, revealing that AalbCYP6Z8 transforms organophosphates through oxidative desulfurization and carbamates through dealkylation and hydroxylation. This work demonstrates that AalbCYP6Z8 is a versatile metabolizer of acetylcholinesterase-inhibiting insecticides.
In this work, covalent organic framework (COF)-derived magnetic nanocomposites (Fe 3 O 4 @PDA@COF TABP ), comprising Fe 3 O 4 as the magnetic core, polydopamine (PDA) as the hydrophilic interlayer, and COF TABP as the outer shell, were first constructed and utilized as the powerful adsorbents for the magnetic solid-phase extraction (MSPE) of pyrethroids (PYRs). The introduction of the PDA coating facilitated the growth of the COF TABP shell and simultaneously provided additional adsorption sites, thereby enhancing the extraction efficiency. Molecular docking simulations revealed that Fe 3 O 4 @PDA@COF TABP exhibited excellent affinity toward PYRs through synergistic π-π stacking, hydrogen bonding, and hydrophobic interactions. The developed MSPE method coupled with GC-μECD exhibited excellent linearity (R 2 ≥ 0.9988), low limits of detection (0.025–0.064 μg kg −1 ), satisfactory recoveries (82.4 %–106.8 %), and low relative standard deviations (RSDs <7.1 %). Finally, the established method was successfully applied to the quantification of trace PYRs in vegetable samples, demonstrating its strong potential for routine pesticide residue monitoring in vegetables.
The increasing persistence of harmful ions and pesticide residues has been a matter of concern due to their pernicious and ubiquitous impact on environmental processes. Herein, we design a ratiometric fluorescent platform for the cascade identification of Cu 2+ and glyphosate, which is devised by grafting rhodamine 6G onto F, N-doped carbon dots (F, N-CDs@Rh6G). The formation of F, N-CDs@Rh6G/Cu 2+ chelation complex induces fluorescence quenching at 438 nm, attributed to static complex formation and photoinduced energy transfer. Subsequently, the introduction of glyphosate reverses the binding priority of the chelated complex and results in the recovery of fluorescence signal at 438 nm, while the reference peak (558 nm) remains relatively stable. Under optimal conditions, the fluorescent probe exhibits the low detection limits (LODs) for Cu 2+ (61 nM) and glyphosate (53 nM). Additionally, a portable microcavity sensing platform combining with smartphone is devised for visual and on-site quantification of Cu 2+ and glyphosate with the exceptional LODs. Therefore, this newly microcavity with F, N-CDs@Rh6G provides a reliable cascade sensing platform for Cu 2+ and glyphosate determination, showcasing potential applications.
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