Single-nanozyme single-readout enabled efficient identification of polyphenols for Chinese tea authentication and brewing evaluation.

With the popularity of health-conscious tea drinking, precise sensing of polyphenols as a main class of antioxidants in tea becomes critical for tea authentication and brewing evaluation. Sensor arrays show great potential for the goal, but currently available sensor arrays always need multiple sensing units and/or multi-dimensional signals, resulting in cumbersome sensor construction and operation as well as data processing. Developing easy-to-fabricate and easy-to-use sensor arrays for efficient discrimination is still challenging.

Cell-Inspired Microreactor with Compartmentalized Active Sites for Development of Cascade Catalysis System in Biosensing.

Enzymatic cascade reactions with high activity and specificity in living cells always benefit from multicompartmentalized organelles that provide separately confined spaces for enzymes, avoiding their mutual interference to ensure the high-efficiency operation of necessary vital movements. Inspired by this, we designed a 3D spherical microreactor (Au@H-APF@Pt) with biomimetic cascade catalysis for glucose detection. First, ultrasmall gold nanoparticles were immobilized in situ on the internal cavities of hollow 3-aminophenol formaldehyde resin (H-APF) nanospheres, along with glucose oxidase activity.

CoMnO Nanoflower-Based Smartphone Sensing Platform and Virtual Reality Display for Colorimetric Detection of Ziram and Cu.

Transition metal doping is an ideal strategy to construct multifunctional and efficient nanozymes for biosensing. In this work, a metal-doped CoMnO nanozyme was designed and synthesized by hydrothermal reaction and high-temperature calcination. Based on its oxidase activity, an "on-off-on" smartphone sensing platform was established to detect ziram and Cu.

Introducing molecular imprinting onto nanozymes: toward selective catalytic analysis.

The discovery of enzyme-like catalytic characteristics in nanomaterials triggers the generation of nanozymes and their multifarious applications. As a class of artificial mimetic enzymes, nanozymes are widely recognized to have better stability and lower cost than natural bio-enzymes, but the lack of catalytic specificity hinders their wider use. To solve the problem, several potential strategies are explored, among which molecular imprinting attracts much attention because of its powerful capacity for creating specific binding cavities as biomimetic receptors.

Triple-Emission Single Sensing Element-Enabled Ratiometric Fluorescent Array Identification of Multiple Antibiotics.

Given that intricate toxicological profiles exist among different antibiotics and pose serious threats to the environment and human health, synchronous analysis of multiple residues becomes crucial. Sensor arrays show potential to achieve the above purpose, but it is challenging to develop easy-to-use and high-sensitivity tools because the state-of-the-art arrays often require more than one recognition unit and are monosignal dependent. Here we exquisitely designed a fluorescent nanoprobe (2-aminoterephthalic acid-anchored CdTe quantum dots with Eu coordination, CdTe-ATPA-Eu) featuring triple emissions at the same excitation as the only element to fabricate a luminescent sensor array with ratiometric calculations for identifying multiple antibiotics.

Target-triggered dual signal amplification based on HCR-enhanced nanozyme activity for the sensitive visual detection of .

The detection of foodborne pathogens is crucial for food hygiene regulation and disease diagnosis. Colorimetry has become one of the main analytical methods in studying foodborne pathogens due to its advantages of visualization, low cost, simple operation, and no complex instrument. However, the low sensitivity limits its applications in early identification and on-site detection for trace analytes.

A single recognition unit-based virtual sensor Array: Applying 3D fluorescence spectroscopy to inner filter effect-based sensing.

A convenient, fast, low-cost detection and discrimination method is demanded for environmental monitoring but still it remains more technological challenges. Herein, we demonstrate that the inner filter effect (IFE), in combination with three-dimensional fluorescence spectroscopy, can offer a virtual sensor array (VSA) as apropersolution. And with the aid of pattern recognition techniques, it is feasible to recognize compounds with structural similarities economically and effectively.

MnO Growth-Induced Luminescence and Oxidase-Like Feature Bimodulation of CePO:Tb Nanorods: Toward Ascorbic Acid-Related Bioanalysis in a "One-Stone-Two-Birds" Manner.

Nanozyme-based multimode detection is a useful means to improve the accuracy and stability of analytical methods. However, both multifunctional nanozymes and related multimodal sensing strategies are still very scarce. Besides, they require complex processes to fabricate and operate.

Multifunctional light-controllable nanozyme enabled bimodal fluorometric/colorimetric sensing of mercury ions at ambient pH.

Nanomaterials with enzyme-like catalytic features (nanozymes) find wide use in analytical sensing. Apart from catalytic characteristics, some other interesting functions coexist in the materials. How to combine these properties to design multifunctional nanozymes for new sensing strategy development is challenging.

Joint concanavalin A-aptamer enabled dual recognition for anti-interference visual detection of Salmonella typhimurium in complex food matrices.

Given that food poisoning and infectious diseases caused by Salmonella typhimurium (S. typhimurium) draw intensive public health concerns, developing rapid, accurate, and cost-effective approaches to detect the pathogen is of crucial importance. Herein, we proposed a concanavalin A (Con A)-aptamer joint strategy to realize dual recognition for the strongly specific, visual, and highly sensitive determination of S.

Alkali-Etched Imprinted Mn-Based Prussian Blue Analogues with Superior Oxidase-Mimetic Activity and Precise Recognition for Tetracycline Colorimetric Sensing.

As a typical antibiotic pollutant, tetracycline (TC) is producing increasing threats to the ecosystem and human health, and exploring convenient means for monitoring of TC is needed. Here, we proposed alkali-etched imprinted Mn-based Prussian blue analogues featuring superior oxidase-mimetic activity and precise recognition for the colorimetric sensing of TC. Simply etching Mn-based Prussian blue analogues (Mn-PBAs) with NaOH could expose the sites and surfaces to significantly improve their catalytic activity.

Amorphous Fe-Containing Phosphotungstates Featuring Efficient Peroxidase-like Activity at Neutral pH: Toward Portable Swabs for Pesticide Detection with Tandem Catalytic Amplification.

Peroxidase-mimetic materials are intensively applied to establish multienzyme systems because of their attractive merits. However, almost all of the nanozymes explored exhibit catalytic capacity only under acidic conditions. The pH mismatch between peroxidase mimics in acidic environments and bioenzymes under neutral conditions significantly restricts the development of enzyme-nanozyme catalytic systems especially for biochemical sensing.

Bifunctional Mn-Doped N-Rich Carbon Dots with Tunable Photoluminescence and Oxidase-Mimetic Activity Enabling Bimodal Ratiometric Colorimetric/Fluorometric Detection of Nitrite.

Multimodal detection is a promising paradigm because of its advantages of expanding usage scenarios and improving reliability. However, it is very challenging to design reasonable strategies to achieve the multimodal sensing of targets. Herein, we developed an unprecedented bimodal ratiometric colorimetric/fluorometric method by exploring a novel bifunctional artificial oxidase mimic, Mn-doped N-rich carbon dots (Mn-CDs), to achieve the high-performance determination of nitrite in complicated matrices.

Smartphone-assisted bioenzyme-nanozyme-chromogen all-in-one test strip with enhanced cascade signal amplification for convenient paraoxon sensing.

Monitoring of pesticide residues in food and environmental matrices is undoubtedly crucial to guarantee food safety and ecological health, yet how to realize their sensitive and convenient detection is still challenging. Herein, we propose an all-in-one test strip that elaborately integrates bioenzyme, nanozyme and chromogen together, and achieve the highly sensitive and convenient sensing of pesticide residues assisted by a smartphone. A sequential self-assembly strategy was first explored to acquire an integrative bioenzyme-nanozyme-chromogen assembly, and then the assembly was confined in a biocompatible hydrogel to construct the test strip.

Nanozymes with Multiple Activities: Prospects in Analytical Sensing.

Given the superiorities in catalytic stability, production cost and performance tunability over natural bio-enzymes, artificial nanomaterials featuring enzyme-like characteristics (nanozymes) have drawn extensive attention from the academic community in the past decade. With these merits, they are intensively tested for sensing, biomedicine and environmental engineering. Especially in the analytical sensing field, enzyme mimics have found wide use for biochemical detection, environmental monitoring and food analysis.

Biomimic Nanozymes with Tunable Peroxidase-like Activity Based on the Confinement Effect of Metal-Organic Frameworks (MOFs) for Biosensing.

Biomimic nanozymes coassembled by peptides or proteins and small active molecules provide an effective strategy to design attractive nanozymes. Although some promising nanozymes have been reported, rational regulation for higher catalytic activity of biomimic nanozymes remains challenging. Hence, we proposed a novel biomimic nanozyme by encapsulating the coassembly of hemin/bovine serum albumin (BSA) in zeolite imidazolate frameworks (ZIF-8) to achieve controllable tailoring of peroxidase-like activity via the confinement effect.

Nanozyme catalysis-assisted ratiometric multicolor sensing of heparin based on target-specific electrostatic-induced aggregation.

Monitoring the level of heparin in clinical matrices is significant because of its pivotal role in preventing thrombosis. Compared to traditional single-signal sensors, multi-signal ratiometric detection can provide anti-interference results especially in complicated environments. However, fabricating an easy-to-operation, low-cost and robust sensor for the ratiometric detection of heparin still remains challenging.

Nanozyme-Participated Biosensing of Pesticides and Cholinesterases: A Critical Review.

To improve the output and quality of agricultural products, pesticides are globally utilized as an efficient tool to protect crops from insects. However, given that most pesticides used are difficult to decompose, they inevitably remain in agricultural products and are further enriched into food chains and ecosystems, posing great threats to human health and the environment. Thus, developing efficient methods and tools to monitor pesticide residues and related biomarkers (acetylcholinesterase and butylcholinesterase) became quite significant.

Dual-mode fluorescence and colorimetric detection of pesticides realized by integrating stimulus-responsive luminescence with oxidase-mimetic activity into cerium-based coordination polymer nanoparticles.

The great threat of pesticide residues to the environment and human health has drawn widespread interest to explore approaches for pesticide monitoring. Compared to commonly developed single-signal pesticide assays, multi-mode detection with inherent self-validation and self-correction is expected to offer more reliable and anti-interference results. However, how to realize multi-mode analysis of pesticides still remains challenging.

Ratiometric Colorimetric Detection of Nitrite Realized by Stringing Nanozyme Catalysis and Diazotization Together.

Due to the great threat posed by excessive nitrite in food and drinking water to human health, it calls for developing reliable, convenient, and low-cost methods for nitrite detection. Herein, we string nanozyme catalysis and diazotization together and develop a ratiometric colorimetric approach for sensing nitrite in food. First, hollow MnFeO (a mixture of Mn and Fe oxides with different oxidation states) derived from a Mn-Fe Prussian blue analogue is explored as an oxidase mimic with high efficiency in catalyzing the colorless 3,3',5,5'-tetramethylbenzidine (TMB) oxidation to blue TMBox, presenting a notable signal at 652 nm.