Controllable Preparation of 2D V₂O₅ Peroxidase‐Mimetic Nanozyme to Develop Portable Paper‐Based Analytical Device for Intelligent Pesticide Assay

Abstract

currently available assays recognize pesticide in solution and usually require massive organic solvents, expensive antibody/ bioenzyme/aptamer, and large instruments, making the analysis of pesticide tedious, lengthy, and impractical. [3,4] Besides the methods mentioned above, the emerging paper analytical devices (PADs) combined with a smartphone is a breeding innovative sensing approach for tackling this issue. To this end, a lot of PADs have been conceived and administered based on the operation mechanism of fluorescence, electrochemistry, electrochemiluminescence, etc. [5] Whereas, these PADs depend on external stimuli, like excitation light or voltage, and apply antibodies or ChE or aptamers as recognition probes, and carry out the detection experiment not only on paper surface but also in solution, which critically affected the lowcost, rapid, portable, and practical analysis of pesticides, making detrimental to large-scale promotion and application. [6,7] Thus, much attention starts to be paid on designing and fabricating novel and high-performance PADs that work only on paper surface without additional recognition elements and external stimuli and are capable of directly and visually probing pesticides by naked eyes.Signal probe, as everyone knows, plays the most important role in deciding the analytical performance of a sensor. With the rapid progress of nanoscience and nanotechnology, nanomaterials possessing catalytic function like bioenzyme, namely nanozymes, have aroused considerable interest and become promising signal probes for pesticide assay. [3,5,8,9] In this context, novel, high-performance, and multifunctional nanozymes are worthy to be discovered for tailor-made utilizations. Among many reported nanozymes, peroxidase-mimetic nanozymes employ H 2 O 2 as the coreactant to catalyze the oxidation of substrates accompanied with the color variation and then could be explored for novel pesticide sensors, especially PADs development. [10] Nevertheless, as far as we are aware, the currently known peroxidase-mimetic nanozymes-based sensors for pesticides suffered from some unavoidable drawbacks. First, almost all of the peroxidase-mimetic nanozymes have the oxidase-mimetic activity, which may affect the detection accuracy via directly catalyzing the oxidation of substrates by O 2 , Given severe harmfulness of pesticides, unique characteristics of peroxidasemimetic nanozymes, and favorable prospects of paper-based analytical devices (PADs), it is highly desirable to construct a nanozyme-based PAD for intelligent analysis of pesticide without enzyme/aptamer/antibody and interference of O 2 . Herein, 2D nanosheet-like V 2 O 5 (2D-VONz) with exclusive peroxidase-mimetic activity is controllably prepared under the optimal reactants concentration and reaction temperature. Experimental characterizations demonstrate that 2D-VONz exhibits high affinity and catalytic rate, and catalytic oxidation is dependent on •OH yielded from the decomposition of H 2 O 2 catalyzed by 2D-VONz, and the catalytic performance is...

Peroxidase-like MoS2/Ag nanosheets with synergistically enhanced NIR-responsive antibacterial activities

“…The local 1 O 2 produced by MoS 2 with 660 nm laser irradiation can create a highly oxidized environment for the activation of metal nanoparticles, resulting in highly toxic metal ions that can induce oxidative stress to kill bacteria ( Wei et al, 2021 ; Hu et al, 2022a ; Li et al, 2022a ; Xue et al, 2023 ). Another advantage of MoS 2 is that it can produce ROS when reacts with hydrogen peroxide (H 2 O 2 ) ( Li et al, 2023b ), hastening the death of bacteria ( Zhao et al, 2015 ). Therefore, combining the characteristics of photodynamic and peroxidase, nanocomposites based on MoS 2 nanosheets could provide a promising alternative for resistant bacterial infections.…”

Self-Supplying of Hydrogen Peroxide/Oxygen Based on CaO2-Co3O4 Cascade Nanoreactors for Cellular Microenvironment Regulation

“… However, these methods face challenges such as a narrow optimal pH range, enzyme vulnerability, and high preparation costs. Alternatively, nanozymes are artificial nanomaterials that exhibit excellent catalytic performance, , simple preparation, good stability, and low preparation cost. − Nanozymes, such as Pt, Au, CeO 2 , and Co 3 O 4 , , , have various mimic enzyme activities, including catalase-like (CAT) activity, and can effectively catalyze intracellular H 2 O 2 to O 2 . This presents an opportunity to facilitate the conversion of H 2 O 2 into O 2 to alleviate hypoxia and decrease the oxidative stress of tumor cells .…”

“…16 MO 2 has recently come under increased scrutiny for its potential to be utilized in tumor nanotherapeutics, thanks to its ability to be decomposed in an acidic tumor microenvironment, releasing metal ions and 13 However, these methods face challenges such as a narrow optimal pH range, enzyme vulnerability, and high preparation costs. Alternatively, nanozymes are artificial nanomaterials that exhibit excellent catalytic performance, 19,20 simple preparation, good stability, and low preparation cost. 21−23 Nanozymes, such as Pt, 24 Au, 25 CeO 2 , 26 and Co 3 O 4 , 27,2827,28 have various mimic enzyme activities, including catalase-like (CAT) activity, and can effectively catalyze intracellular H 2 O 2 to O 2 .…”

Iridium Complex with Specific Intercalation in the G-Quadruplex: A Phosphorescence and Electrochemiluminescence Dual-Mode Homogeneous Biosensor for Enzyme-Free and Label-Free Detection of MicroRNA

“…4−6 Here, we proposed a new method for measuring miRNA with high sensitivity and selectivity by a dual-mode homogeneous biosensor, which could address the obstacles of miRNAs including the low expression level, few nucleotides, sequence homology, and easy degradation. 7,8 At present, the most commonly used approaches to miRNA analysis were proposed based on luminescent, 9,10 electrochemical, 11,12 miRNA-Seq, 13 and quantitative real-time polymerase chain reaction (qPCR) techniques. 14 Nevertheless, no matter what technique, the most important part of a sensor is a signal emitter, which decides the analytical performance.…”

“…MicroRNA (miRNA) is a type of single-stranded RNA molecule, approximately 22 nucleotides long, produced within cells to regulate gene expression. − The aberrant expression level of certain miRNA in biological liquids is associated with many illnesses, especially cancers. − Here, we proposed a new method for measuring miRNA with high sensitivity and selectivity by a dual-mode homogeneous biosensor, which could address the obstacles of miRNAs including the low expression level, few nucleotides, sequence homology, and easy degradation. , …”