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As pure antipodes may differ in biological interactions, pharmacology, and toxicity, discrimination of enantiomers is important in the pharmaceutical and agrochemical industries. Two major challenges in enantiomer determination are transducing and amplifying the distinct chiral-recognition signals. In this study, a light-sensitive organic photoelectrochemical transistor (OPECT) with homochiral character is developed for enantiomer discrimination. Demonstrated with the discrimination of glucose enantiomers, the photoelectrochemically active gate electrode is prepared by integrating Au nanoparticles (AuNPs) and a chiral Cu(II)-metal-organic framework (c-CuMOF) onto TiO 2 nanotube arrays (TNT). The captured glucose enantiomers are oxidized to hydrogen peroxide (H 2 O 2 ) by the oxidase-mimicking AuNPs-loaded c-CuMOF. Based on the confinement effect of the mesopocket structure of the c-CuMOF and the remarkable charge transfer ability of the 1D nanotubular architecture, variations in H 2 O 2 yield are translated into significant changes in OPECT drain currents (I D ) by inducing a catalytic precipitation reaction. Variations in I D confer a sensitive discrimination of glucose enantiomers with a limit of detection (LOD) of 0.07 μM for L-Glu and 0.05 μM for D-Glu. This enantiomer-driven gate electrode response strategy not only provides a new route for enantiomer identification, but also helps to understand the origin of the high stereoselectivity in living systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Developing an accurate, cost-effective, reliable, and stable glucose detection sensor for the food industry poses a significant yet challenging endeavor. Herein, we present a silver nanoparticle-decorated titanium dioxide nanoribbon array on titanium plate (Ag@TiO 2 /TP) as an efficient electrode for non-enzymatic glucose detection in alkaline environments. Electrochemical evaluations of the Ag@TiO 2 /TP electrode reveal a broad linear response range (0.001 mM - 4 mM), high sensitivity (19,106 and 4264 μA mM -1  cm -2 ), rapid response time (6 s), and a notably low detection limit (0.18 μM, S/N = 3). Moreover, its efficacy in measuring glucose in beverage samples shows its practical applicability. The impressive performance and structural benefits of the Ag@TiO 2 /TP electrode highlight its potential in advancing electrochemical sensors for small molecule detection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

An enzymatic fluorescent probe is developed for the selective detection of glucose. In this work, a Bovine Serum Albumin stabilized gold nanocluster (BSA-AuNCs) was synthesized by microwave assisted method, and it is modified with glucose oxidase, thereby a fluorescent enzymatic sensor (BSA-AuNCs@GoX) was designed for the sensitive detection of glucose with a limit of detection of 0.03 mM. The red fluorescence exhibited by the probe is quenched by the production of H 2 O 2 on addition of glucose via. a static quenching mechanism from UV visible absorption and Fluorescence lifetime results. The developed probe exhibits good selectivity and sensitivity with other coexisting molecular species such as glycine, creatinine, methionine, histidine, uric acid, albumin, and ions such as sodium, potassium, calcium, magnesium, zinc etc. that appear in the body fluid. The practical applicability was studied in paper strip and extended its reproducibility in biological matrixes such as human serum and urine and found a good recovery percentage of 94-101 %. By this way, we have fabricated an effective fluorescent enzymatic "turn-off" sensing probe for the detection of glucose., (© 2024 Wiley-VCH GmbH.)

In this work, we propose a blossom-like Ni, Co bimetallic metal-organic framework (NiCo-MOF) synthesized hydrothermally and decorated with silver nanoparticles (AgNPs) via chemical reduction for electrochemical enzyme-free glucose sensing. The NiCo-MOF nanostructures had large specific surface area and good sensing performance. The AgNPs enhanced the electrochemical performance of the MOF, resulting in excellent electrochemical activity. The sensor exhibited sensitivities of 1191.84 and 271.19 μA mM -1 cm -2 in the linear ranges of 0.005-1.125 and 1.525-5.325 mM, respectively, with a detection limit of 2.3 μM. The sensor was successfully applied for glucose determination in Huangshui (HS) using an artificial neural network as machine learning (ML) model. The R 2 value near 1, low RMSE, and high RPD values of the proposed ML model demonstrate its excellent fitting and prediction performance. This will provide a fast and portable intelligent sensing analysis technology for the detection of glucose in HS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

It was speculated that estrogen-like compounds may be produced by chemical reactions during food processing, such as Maillard reaction, which would disrupt the endocrine system of organisms. Herein, the Maillard reaction in the process of high temperature for long time was simulated by using model system, and unknown estrogen-like compounds produced during Maillard reaction were screened by colorimetric assay based on dual estrogen receptor (ER)-gold nanoparticles (AuNPs) and enzyme-linked immunosorbent assay (ELISA). Possible structures of estrogen-like compounds were inferred by ultra-performance liquid chromatography-quadrupole time of flight tandem mass spectrometry (UPLC-QTOF/MS) in combination with a mass database, and finally the structure of estrogen-like compound, 2, 4-dihydroxy-1, 4-benzoxazin-3-one-2-o-β-D-glucopyranoside (DIBOA-glc), was identified by high resolution orbitrap mass spectrometry (Orbitrap HRMS). This is the first study of the screening and identification of unknown estrogen-like compounds produced in Maillard reaction. Additionally, strategy of controlling the formation of DIBOA-glc by adding vitamin B6 in Maillard reaction was proposed, providing effective proposals for the safety control in actual food processing., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Classical luminol-based chemiluminescence (CL) is the process of emitting light enhanced by the addition of coreactant hydrogen peroxide (H 2 O 2 ). To address the instability issue of H 2 O 2 decomposition, herein, we proposed a nanozyme-based biofuel cell (BFC) ingeniously coupled with a luminol CL system via in situ generation of H 2 O 2 . Specifically, the gold nanoparticle (AuNP) nanozyme with glucose oxidase-like activity can act as the anodic enzyme of BFC to catalyze the oxidation of glucose to produce H 2 O 2 and electrons. In this case, H 2 O 2 as a coreactant enhanced the CL intensity and the cathode of the BFC obtained electrons to generate the open circuit voltage ( E OCV ) signals. As a result, a dual-signal biosensing platform was successfully constructed. Interestingly, the AuNPs-catalyzed system operates in an alkaline medium, which precisely meets the pH requirement for luminol luminescence. Such a BFC-CL system not only greatly lessens the effect of unstable exogenous H 2 O 2 on the signal stability but also enhances the CL of luminol. Furthermore, both CL and E OCV signals present a positive correlation with the glucose concentration. Therefore, this novel BFC-CL system shows good performance for dual-signal biosensing, which would serve as a valuable guideline for the design and application of BFC-based self-powered or CL biosensors.

An electrochemical glucose sensor based on flexible materials is significant for wearable devices used for real-time health monitoring and diagnosis. However, applying flexible electrodes involves complex fabrication processes and might reduce detection sensitivity. To overcome these obstacles, we herein report a novel strategy for preparing a highly flexible enzyme electrode based on an electrospun poly(vinyl alcohol) (PVA) mat decorated with in situ grown silver nanoparticles (nano-Ag) for electrochemical glucose sensing. Ferrocene (Fc) was selected as an electron acceptor for glucose oxidase (GOD) in order to minimize the influence of oxygen. Electron transfer between GOD and Fc was facilitated by confining them within a mixed self-assembled monolayer (SAM) formed on a thin layer of gold deposited on top of the PVA/nano-Ag film. Nano-Ag was found to significantly increase the surface area of the electrode and improve the stability of electrode conductivity during tensile deformation. Electrochemical glucose detection was performed by chronoamperometry in the electroactivity domain of ferrocene, and good linearity ( R 2 = 0.993) was obtained in the range of 0.2-7 mM with a detection limit of 0.038 mM and a relative standard deviation (RSD) of 1.45% ( n = 6). After being stuck to a bendable PDMS slice and bent, respectively, at 30° and 60° 50 times, the electrode showed slight changes in detection results (<4.78%), which remained within 8% when the bending angle increased to 90°. With its high flexibility, good detection performance, and convenient fabrication process, the proposed enzyme electrode showed good potential as a flexible platform for wearable glucose sensing systems.

Glucose oxidase (GOx)-based electrodes are important for bioelectronics, such as glucose sensors. It is challenging to effectively link GOx with nanomaterial-modified electrodes while preserving enzyme activity in a biocompatible environment. To date, no reports have used biocompatible food-based materials, such as egg white proteins, combined with GOx, redox molecules, and nanoparticles to create the biorecognition layer for biosensors and biofuel cells. This article demonstrates the interface of GOx integrated with egg white proteins on a 5 nm gold nanoparticle (AuNP) functionalized with a 1,4-naphthoquinone (NQ) and conjugated with a screen-printed flexible conductive carbon nanotube (CNT)-modified electrode. Egg white proteins containing ovalbumin can form three-dimensional scaffolds to accommodate immobilized enzymes and adjust the analytical performance. The structure of this biointerface prevents the escape of enzymes and provides a suitable microenvironment for the effective reaction. The bioelectrode's performance and kinetics were evaluated. Using redox-mediated molecules with the AuNPs and the three-dimensional matrix made of egg white proteins improves the transfer of electrons between the electrode and the redox center. By engineering the layer of egg white proteins on the GOx-NQ-AuNPs-mediated CNT-functionalized electrodes, we can modulate analytical performances such as sensitivity and linear range. The bioelectrodes demonstrate high sensitivity and can prolong the stability by more than 85% after 6 h of continuous operation. The use of food-based proteins with redox molecule-modified AuNPs and printed electrodes demonstrates advantages for biosensors and energy devices due to their small size, large surface area, and ease of modification. This concept holds a promise for creating biocompatible electrodes for biosensors and self-sustaining energy devices.

Continuous glucose meters (CGMs) have tremendously boosted diabetes care by emancipating millions of diabetic patients' need for repeated self-testing by pricking their fingers every few hours. However, CGMs still suffer from major deficiencies regarding accuracy, precision, and stability. This is mainly due to their dependency on an enzymatic detection mechanism. Here a low-cost hydrogel microneedle (HMN)-CGM assay fabricated using swellable dopamine (DA)-hyaluronic acid (HA) hydrogel for glucose interrogation in dermal interstitial fluid (ISF) is introduced. Platinum and silver nanoparticles are synthesized within the 3D porous hydrogel scaffolds for nonenzymatic electrochemical sensing of the glucose. Incorporation of a highly water dispersible conductive polymer, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) enhances the electrical properties of HMN array, making the patch suitable as the working electrode of the sensor. The in vitro and ex vivo characterization of this newly developed HMN patch is fully studied. The performance of the HMN-CGM for real-time measurement of glucose is also shown using a rat model of type 1 diabetes. The device introduces the first HMN-based assay for tracking important disease biomarkers and expect to pave the way for next generation of polymeric-based sensors., (© 2022 Wiley-VCH GmbH.)

Rapid and accurate blood glucose detection is significant for diagnosing and treating diabetes. Herein, ultra-low-content gold nanoparticles were loaded on different metal foams and applied to electrochemical enzyme-free glucose sensors via simple displacement reactions. The structures and properties of the produced catalysts were determined by various characterization methods. The performance of the glucose sensor was examined in relation to the interactions between three different metal substrates and gold. The one with the best performance is the sample of gold nanoparticles grown on copper foam (Au300 Cu Foam). It has the advantage of a porous three-dimensional network, a large electroactive surface area, and the high catalytic activity of gold. The combination of Cu and Au increased the valence state of Au, thus favoring the catalytic activity for glucose oxidation. Cyclic voltammetry and chronoamperometry measurements revealed that Au is responsible for the electrocatalytic oxidation of glucose. The sensitivity of Au300 Cu Foam was found to be 10 839 μA mM -1 cm -2 in the linear range of 0.00596-0.0566 mM, with a detection limit (LOD) of 0.223 μM, and 2-3 s response time at 0.4 V vs. Ag/AgCl. The Au300 Cu Foam glucose sensor also offered outstanding stability and anti-interference performance. The prepared Au300 Cu Foam electrode was also successfully applied to detect different levels of glucose in human body fluids, such as saliva. These characteristics make Au300 Cu Foam promising for non-invasive glucose detection.

This work presents the development of a membraneless single-enzyme biofuel cell powered by glucose (GBFC). The GBFC biocathode is based on a graphite rod electrode (GRE) coated with a layer of Prussian blue (PB) nanoparticles entrapped into poly(pyrrole-2-carboxylic acid) (PPCA) shell, an additional layer of PPCA, and covalently to polymer linked glucose oxidase (GOx). The bioanode is based on GRE modified with a nanobiocomposite composed of poly(1,10-phenanthroline-5,6-dione), gold nanoparticles entrapped in a PPCA shell, and GOx linked by an amide bond to polymer. The operation of the developed single-enzyme GBFC is based on GOx-catalysed oxidation of glucose on both the bioanode and biocathode and reduction of H 2 O 2 electrocatalysed by PB on the biocathode. The GBFC operated in O 2 -saturated buffer medium pH 6.0 containing glucose. An open-circuit voltage (OCV) of 646 mV, a maximum power density of 10.94 μW/cm 2 and a current density of 60.52 μA/cm 2 at 40 mM glucose were determined. OCV and current density were directly proportional to glucose concentration in 0.01-10.00 mM and 0.05-124.00 mM concentration ranges, respectively. In addition, GBFC had good operational stability and retained more than 90% of the initial OCV after 36 days., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The development of responsive materials in a predictable manner is high on the list of the material industry's trends. In this work, responsive Ag@NiCo 2 O 4 nanowires were, firstly, anchored on N-doped carbon cloth (NC) and, then, employed as array electrodes for a nonenzymatic glucose-sensing application. The results showed that the highly conductive NiCo 2 O 4 nanowires supported Ag nanoparticles and exhibited high conductivity and electrocatalytic properties. The fully exposed crystalline planes of Ag nanoparticles provided more active surface sites. As a result, the assembled Ag@NiCo 2 O 4 -NC electrodes for the glucose-sensing evaluation delivered a selectivity of 2803 μA mM -1 cm -2 and a detection limit of 1.065 μM, which outperformed the literature-reported Ag- and NiCo 2 O 4 -based glucose-sensing catalysts.

This article reports a facile fabrication of a highly sensitive enzyme-free sweat glucose sensor over Whatman filter paper substrate employing a dual-step pencil and pen approach. Initially, two pencil-drawn electrodes (PDEs) are obtained on the filter paper through the manual abrasion of an 8B graphite pencil. Then, the sensing layer is drawn over one of the PDEs using a custom-made copper (Cu) nanoparticle ink (CuNP-ink) pen to form copper nanoparticle ink decorated PDE (CuNP-ink/PDE) which serves as a working electrode, while the other PDE is drawn with silver conductive ink (Ag-ink) pen to form reference electrode. The developed CuNP-ink/PDE is composed of 43.5% of metallic Cu nanoparticles, inducing a highly crystalline and conductive nature, thus promoting fast electron transfer during glucose electrooxidation. The developed sensor offers a sensitivity of 2691.7 μAmM -1 cm -2 , a detection limit of 0.5 μM, a linear range of 1.2-40 μM, and a fast response time of ∼ 1.5 s. Besides, the sensor measurements are stable, reproducible, and selective in glucose sensing. Also, the reliability of the sensor is tested by comparing its performance with a UV-Visible spectrophotometer for proving its efficacy in sweat glucose detection. Experimental results evince the effectiveness of the designed sensor for glucose detection in human sweat., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Amarprit Singh reports financial support was provided by Department of Science and Technology, Govt. of India., (Copyright © 2022 Elsevier B.V. All rights reserved.)

As a nanozyme, gold nanoparticles have some advantages compared with natural enzymes, such as stable structure, adjustable catalytic activity, multifunctionality, and recyclability. Due to their special dimension, they are easy to aggregate rapidly and lose their catalytic performance when exposed to normal saline or special pH environment. To avoid such a situation, Au@PNIPAm nanozymes with core-shell structure are constructed and their mimic peroxidase and glucose oxidase enzymatic activities are investigated. Kinetic examinations manifest that Au@PNIPAm nanozymes exhibited a high affinity for 3,3,5,5-tetramethylbenzidine (TMB), hydrogen peroxide (H 2 O 2 ), and glucose. These predominant peroxidase-like and glucose-like oxidase Au@PNIPAm catalytic activities are successfully used in the detection of H 2 O 2 or glucose (LOD is 2.43 mM or 5.07 mM). Otherwise, the potential Au@PNIPAm nanozymes are provided with a clear ability for decomposing the intracellular H 2 O 2 in living cells. And it could protect cells from oxidative stress damage with inducing by H 2 O 2 . Therefore, it is easy to consider that Au@PNIPAm nanozymes show a certain possibility to retard cell senescence and increase the production of the hydroxyl radical which could prevent carcinogenesis of the cell.

To maximize the potential of 5G infrastructure in healthcare, simple integration of biosensors with wireless tag antennas would be beneficial. This work introduces novel glucose-to-resistor transduction, which enables simple, wireless biosensor design. The biosensor was realized on a near-field communication tag antenna, where a sensing bioanode generated electrical current and electroreduced a nonconducting antenna material into an excellent conductor. For this, a part of the antenna was replaced by a Ag nanoparticle layer oxidized to high-resistance AgCl. The bioanode was based on Au nanoparticle-wired glucose dehydrogenase (GDH). The exposure of the cathode-bioanode to glucose solution resulted in GDH-catalyzed oxidation of glucose at the bioanode with a concomitant reduction of AgCl to highly conducting Ag on the cathode. The AgCl-to-Ag conversion strongly affected the impedance of the antenna circuit, allowing wireless detection of glucose. Mimicking the final application, the proposed wireless biosensor was ultimately evaluated through the measurement of glucose in whole blood, showing good agreement with the values obtained with a commercially available glucometer. This work, for the first time, demonstrates that making a part of the antenna from the AgCl layer allows achieving simple, chip-less, and battery-less wireless sensing of enzyme-catalyzed reduction reaction.

The aim of this work was to gain insights into the role of manganese in MnSBA-15 support for gold in the base-free glucose oxidation with H 2 O 2 using a microwave reactor. MnSBA-15 (manganese-acidity source) and SBA-15 (for comparison) were modified with Au (2.2 wt. %) and Cu (for comparison). The physicochemical properties of the catalysts were investigated by XRD, N 2 ads/des, TEM, UV-vis, XPS, pyridine adsorption combined with FTIR, ATR-FTIR, and 2-propanol decomposition. The effects of the Mn presence in the support, Au NPs size that determines the number of active Au centers, and the Fermi energy (E F ), together with the effects of the pore size, reaction temperature, and time on the activity and selectivity of the applied catalysts were assessed and discussed. It has been demonstrated that the presence of Mn generated Lewis acid centers which did not participate in glucose and H 2 O 2 adsorption, and thus, were not directly involved in the reaction pathway. Both reagents were adsorbed on gold nanoparticles. H 2 O 2 was decomposed to molecular oxygen which oxidized glucose to gluconic acid (50-90% of glucose conversion depending on the reaction time and ~100% selectivity). The presence of manganese in MnSBA-15 was responsible for increased Au NPs size and only slightly influenced the negative charge on gold particles. To achieve effective activity a compromise between the number of active gold species and the level of E F has to be reached (for 5.7 nm Au NPs).

In this work, a flexible amphiprotic amino-bonded carbon nanotube-Ag nanoparticle/polystyrene (CNT-NH 2 -Ag/PS) paper electrode was fabricated to measure glucose in human body fluids by a combination of vacuum filtration and high temperature baking. The front side of the fabricated paper electrode was hydrophobic and conductive, whereas its back side was hydrophilic and nonconductive. In the fabrication process, the coating sequence of CNT-NH 2 , Ag and PS was critical to determine the performance of the resulting CNT-NH 2 -Ag/PS electrode besides other parameters ( e.g. , amount of soluble starch, PS and Ag nanoparticles, type and amount of CNT-NH 2 , and electrode sensing area). Based on a series of experimental observations, the possible mechanism of glucose detection on the paper electrode was proposed, in which glucose was more favorable to migrate to the hydrophilic back side of the paper and interact with the active species ( e.g. , O 2 - ) on the electrode surface. The electrochemical results showed that the CNT-NH 2 -Ag/PS paper electrode maintained stable electrochemical properties even after five cycles of use and 60 days of storage in air. The amphiprotic paper electrode demonstrated excellent sensing performance for glucose with a linear range of 1 μM to 1000 μM, a low detection limit of 0.2 μM, and a sensitivity of 31 333.0 μA mM -1 cm -2 . The fabricated paper electrode was also successfully applied to detect different levels of glucose in complex human body fluids such as saliva, urine, and serum. These features make this type of paper electrode promising for glucose measurement.

This work focuses on the fabrication of non-enzymatic glucose sensing materials based on laser-formed Au nanoparticles embedded in Ti-textured substrates. Those materials possess good catalytic activity toward glucose oxidation in 0.1 × phosphate buffered saline as well as resistance to some interferants, such as ascorbic acid, urea, and glycine. The electrodes are further coated with three different polymers, that is, Nafion, photo-crosslinked poly(zwitterions) based on sulfobetaine methacrylate, and a hybrid membrane consisting of both polymers. Both the optimal integrity of the material and its catalytic activity toward glucose oxidation were maintained by the hybrid membranes with a large excess of poly(zwitterions) (mass ratio 20:1). The chemical structures of the as-formed membranes are confirmed by Fourier transform infrared spectroscopy. Due to the zwitterionic nature of the coating, the electrodes are resistant to biofouling and maintain electrochemical activity toward glucose for 4 days. Moreover, due to the synergistic effect of both Nafion and poly(zwitterions), the interference from the two compounds, namely, from acetylsalicylic acid and acetaminophen, was diminished. Besides the presence of polymer membranes, the electrode possesses a sensitivity of 36.8 μA cm -2  mM -1 in the linear range of 0.4-12 mM, while the limit of detection was estimated to be 23 μM. Finally, the electrodes are stable, and their response is not altered even by 1,000 bending cycles., (© 2021 Wiley Periodicals LLC.)

Chains of nickel nanoparticles coated with few nitrogen-doped graphitic carbon layers (Ni@NC) are synthesized by hydrogen-assisted pyrolysis of Ni-ZIF. Hydrogen and temperature can play key roles in the formation of oriented Ni@NC nanoparticle chains, and carbon shells can protect Ni nanoparticles from external oxidation and aggregations. Under the optimized potential (0.60 V vs. Ag/AgCl), the Ni@NC7H nanoparticle chains obtained at 700 °C under H 2 /Ar atmosphere (Ni@NC7H) demonstrate outstanding performances, such as high sensitivity of 1.44 mA mM -1  cm -2 (RSD = 1.0%), low detection limit of 0.34 μM (S/N = 3), broad linear range from 1 μM to 1.81 mM, and excellent application potential in artificial sweat and human serum. Therefore, the findings above indicate that this study will provide a general methodology for the synthesis of chains-like core-shell nanoparticle electrocatalysts for non-enzymatic glucose detection., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Aqueous colloids, consisting of 15-30 nm-sized silver nanoparticles (Ag NPs), were prepared using the reducing and stabilizing abilities of glucose, sucrose, and dextran. The long-term stability of coated Ag NPs increases from glucose over sucrose to dextran, i.e., with the increase of the molecular weight of carbohydrate molecules. The density functional theory (DFT) calculations of the partial atomic (Mulliken) charges and adsorption energies are applied to explain the enhanced stability of coated Ag NPs. All coated Ag NPs have a significantly broader concentration range of nontoxic behavior toward pre-osteoblast cells than bare Ag NPs prepared using sodium borohydride. The carbohydrate-coated Ag NPs display the same level of toxic ability against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria as bare Ag NPs. The differences in toxicity mechanism of the coated and bare Ag NPs are a consequence of the absence and presence of co-occurring Ag + ions in examined dispersion, respectively., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Raman spectroscopy coupled with confocal microscopy offers an alternative bioimaging technique overcoming limitations associated with sensitivity, tissue penetration and image resolution. Allied to the surface-enhanced Raman scattering (SERS) properties of gold nanoparticles (AuNP), we designed SERS nanoprobes with enhanced properties and straightforward application as bio-labelling agents for gliomas. The ensuing nanoprobes coated with simple sugar units (galactose or glucose) allowed assessing information about their intracellular localization (vesicular structures), with impressive sensitivity towards complex environments and proved the ability to overcome biological auto-fluorescence and high penetration in tissues. We validate the use of sugars as an all-in-one vector (Raman reporter, conferring high stability, biocompatibility and affinity to glioma cells) as imaging agents using an impressive technique.

Microbial adhesion to host cells represents the initial step in the infection process. Several methods have been explored to inhibit microbial adhesion including the use of glycopolymers based on mannose, galactose, sialic acid and glucose. These sugar receptors are, however, abundant in the body, and are not unique to bacteria. Trehalose, in contrast, is a unique disaccharide that is widely expressed by microbes. This carbohydrate has not yet been explored as an anti-adhesive agent. Herein, gold nanoparticles (AuNPs) coated with trehalose-based polymers were prepared and compared to glucose-functionalized AuNPs and examined for their ability to prevent binding to endothelial cells. Acting as anti-adhesive agents, trehalose-functionalized NPs decreased the binding of S. aureus to HUVECs, while outperforming the control NPs. Microscopy revealed that trehalose-coated NPs bound strongly to S. aureus compared to the controls. In conclusion, nanoparticles based on trehalose could be a non-toxic alternative to inhibit S. aureus infection., (© 2021 Wiley-VCH GmbH.)

Nanozyme has been regarded as one of the antibacterial agents to kill bacteria via a Fenton-like reaction in the presence of H 2 O 2 . However, it still suffers drawbacks such as insufficient catalytic activity in near-neutral conditions and the requirement of high H 2 O 2 levels, which would minimize the side effects to healthy tissues. Herein, a mesoporous ceria hollow sphere/enzyme nanoreactor is constructed by loading glucose oxidase in the mesoporous ceria hollow sphere nanozyme. Due to the mesoporous framework, large internal voids, and high specific surface area, the obtained nanoreactor can effectively convert the nontoxic glucose into highly toxic hydroxyl radicals via a cascade catalytic reaction. Moreover, the generated glucose acid can decrease the localized pH value, further boosting the peroxidase-like catalytic performance of mesoporous ceria. The generated hydroxyl radicals could damage severely the cell structure of the bacteria and prevent biofilm formation. Moreover, the in vivo experiments demonstrate that the nanoreactor can efficiently eliminate 99.9% of bacteria in the wound tissues and prevent persistent inflammation without damage to normal tissues in mice. This work provides a rational design of a nanoreactor with enhanced catalytic activity, which can covert glucose to hydroxyl radicals and exhibits potential applications in antibacterial therapy.

Nanotechnology-based packaging may improve food quality and safety, but packages manufactured with polymer nanocomposites (PNCs) could be a source of human dietary exposure to engineered nanomaterials (ENMs). Previous studies showed that PNCs release ENMs to foods predominantly in a dissolved state, but most of this work used food simulants like dilute acetic acid and water, leaving questions about how substances in real foods may influence exposure. Here, we demonstrate that food and beverage ingredients with reducing properties, like sweeteners, may alter exposure by inducing nanoparticle formation in foods contacting silver nanotechnology-enabled packaging. We incorporated 12.8 ± 1.4 nm silver nanoparticles (AgNPs) into polyethylene and stored media containing reducing ingredients in packages manufactured from this material under accelerated room-temperature and refrigerated conditions. Analysis of the leachates revealed that reducing ingredients increased the total silver transferred to foods contacting PNC packaging (by as much as 7-fold) and also induced the (re)formation of AgNPs from this dissolved silver during storage. AgNP formation was also observed when Ag + was introduced to solutions of natural and artificial sweeteners (glucose, sucrose, aspartame), commercial beverages (soft drinks, juices, milk), and liquid foods (yogurt, starch slurry), and the amount and morphology of reformed AgNPs depended on the ingredient formulation, silver concentration, storage conditions, and light exposure. These results imply that food and beverage ingredients may influence dietary exposure to nanoparticles when PNCs are used in packaging applications, and the practice of using food simulants may in certain cases underpredict the amount of ENMs likely to be found in foods stored in these materials.

In this work, an S hybrid nanosheet with multiple functions is synthesized by in situ modification of gold nanoparticles (AuNPs) onto two-dimensional (2D) metalloporphyrinic metal-organic framework (MOF) (Cu-tetra(4-carboxyphenyl)porphyrin chloride(Fe(III)), designated as AuNPs/Cu-TCPP(Fe). Cu-TCPP(Fe) nanosheets contribute peroxidase-like activity, and AuNPs have glucose oxidase (GOx) mimicking performance, which induce the cascade catalysis reactions to convert glucose into hydrogen peroxide (H 2 O 2 ), and then, by using AuNP catalysis, H 2 O 2 oxidizes the no Raman-active leucomalachite green (LMG) into the Raman-active malachite green (MG). Simultaneously, in the presence of AuNPs, sensitive and selective surface-enhanced Raman scattering (SERS) determination of glucose can be achieved. The bioenzyme-free SERS assay based on such AuNPs/Cu-TCPP(Fe) nanosheets is used for detection of glucose in saliva, showing good recovery from 96.9 to 100.8%. The work paves a new way to design a nanozyme-based SERS protocol for biomolecule analysis.

Although core-shell structure is favored by many applications, preparing it with green way is rarely been reported. Herein, a core-shell structured Cu@Pd-CS nanocomposite is greenly fabricated utilizing a natural chitosan and applied to glucose detection. As-obtained Cu@Pd-CS nanoparticles were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). When applied to glucose detection, the Cu@Pd-CS exhibits good stability, sensitivity and anti-interference. Moreover, it has a good linear relationship in glucose concentrations range of 0.1-1 mM with the sensitivity of 1.53 μA mM -1 cm -2 and 1-10 mM with the sensitivity of 23.00 μA mM -1 cm -2 . This work proves the practicability of building metal-based core-shell structure nanoparticles with green resources and glucose detection application., (Copyright © 2020. Published by Elsevier Ltd.)

Malaria, a mosquito-borne disease caused by Plasmodium species, claims more than 400,000 lives globally each year. The increasing drug resistance of the parasite renders the development of new anti-malaria drugs necessary. Alternatively, better delivery systems for already marketed drugs could help to solve the resistance problem. Herein, we report glucose-based ultra-small gold nanoparticles (Glc-NCs) that bind to cysteine-rich domains of Plasmodium falciparum surface proteins . Microscopy shows that Glc-NCs bind specifically to extracellular and all intra-erythrocytic stages of P. falciparum . Glc-NCs may be used as drug delivery agents as illustrated for ciprofloxacin, a poorly soluble antibiotic with low antimalarial activity. Ciprofloxacin conjugated to Glc-NCs is more water-soluble than the free drug and is more potent. Glyco-gold nanoparticles that target cysteine-rich domains on parasites may be helpful for the prevention and treatment of malaria.

ZnO nanorods (NRs) synthesized by a hydrothermal method and decorated with Au nanoparticles (NPs) were used for fluorescent non-enzymatic glucose detection. The detection is based on the photoluminescence (PL) quenching of ZnO NRs/Au NPs (at 382 nm under 325 nm excitation) exposed to glucose. The sensor exhibits a high sensitivity of (22 ± 2) % mM -1 (defined as percentage change of the PL peak intensity per mM) and a limit of detection (LOD) as low as 0.01 mM, along with an excellent selectivity and a short response time (less than 5 s). In comparison with a fluorescent non-enzymatic ZnO nanostructure-based glucose sensor, the addition of Au NPs significantly enhances the sensitivity. This is attributed to the surface plasmon resonance, which increases not only the photoluminescence intensity but also the photo-oxidation property of the ZnO NRs. Thus, ZnO NRs/Au NPs can act as an efficient photocatalyst for glucose detection. Most importantly, the probe is applicable to glucose detection in human blood serum. The outstanding performance of the material and its cost-effectiveness allow for potential application in single-use, noninvasive glucose devices.Graphical abstract A sensitive non-enzymatic fluorescent glucose probe-based ZnO nanorod decorated with Au nanoparticles.

Bifunctional candidates, which could provide catalytic and plasmonic properties simultaneously, could activate a promising development for biomedicine. Here, we kinetically controlled and synthesized a penta-twinned icosahedral Au (Ih Au) by a facile wet-chemical protocol without assistance of stabilizers. Benefiting from icosahedral morphology and kinetic synthesis process, the Ih Au nanoparticles (NPs) incorporate three key advantages: (i) ample active sites/"hot spots" and surface strain, (ii) good stability/chemical inertness and easy functionalization, and (iii) biological compatibility and a clean surface, which could promote their electrocatalysis and photonic capacity. Ih Au NPs, as bifunctional nanomaterials, exert excellent electrocatalytic and surface-enhanced Raman scattering (SERS) performances. Ih Au delivers the highest glucose electrooxidation (GEO) peak current density with 6.87 mA cm -2 , which is 14 times larger than that of Turkevich Au (0.49 mA cm -2 ) under the same condition. Moreover, the SERS signals of rhodamine 6G (R6G) on Ih Au are much stronger than that on the other corresponding Au counterparts. Particularly, the SERS intensity of R6G on Ih Au increases by about four times compared to that on Au NPs. This study motivates the great prospect for combining Ih Au's bifunctionalities and indicates the potential of bifunctional nanomaterials in biologically implanted devices.

Fundamental understandings and precise control of nanoparticle growth in the complex biological environment are crucial to broadening their potential applications in tissue imaging. Herein, we report that glutathione (GSH), a widely used capping ligand for precise control of the size of gold nanoparticle (AuNP) down to single-atom level in test tubes, can also be used to direct the selective growth of the AuNPs in the mitochondria of renal tubule cells as well as hippocampus cells in the tissues. Precise control of this growth process can lead to the formation of both ultrasmall AuNPs with near-infrared luminescence and large plasmonic AuNPs. The observed selective growth of the AuNPs is likely due to unique GSH storage function of the mitochondria. Using a different ligand, β-glucose thiol, we also found that the brush border of the intestine for glucose absorption became the major site for the growth of luminescent AuNPs. These findings suggest that selective growth of AuNPs in the biological tissues can indeed be directed with specific ligands, opening up a new avenue to tissue labeling and future development of artificial bionano hybrid systems.

As typical glucose oxidase nanozymes, gold nanoparticles (Au NPs) have attracted much attention due to their wide-ranging applications. Ligand caps, as the "cure-all solution" for NPs, not only play important roles in the size and shape control of Au NPs but also influence their catalytic activity and selectivity. A deep understanding of the catalytic mechanism and precise description of the important role of ligands can provide possible ways to design functional Au NPs. Here, with the specific example of Au(111) capped with chiral phenylalanine (Phe), the chiral selective oxidation mechanism of glucose and the important role of the ligands were studied via first-principles calculations. All results show that the dehydrogenation of glucose to form glucono delta-lactone (GDL) is favored on clean Au(111), while the subsequent hydrolysis of GDL is the rate-limiting step for glucose oxidation. The flat and nonchiral Au(111) surface shows negligible selectivity in relation to the oxidation of d- and l-glucose, while chiral Phe-Au(111) shows selective adsorption towards d- and l-glucose. l-Phe-capped Au(111) prefers to adsorb d-glucose, while d-Phe-capped Au(111) prefers to adsorb l-glucose. Considering the three steps in the capped ligand catalysis (adsorption, replacement and reaction), we propose that the ligands play key roles in selectively adsorbing reactants before the subsequent exchange and reaction steps.

Biological modifications of the silk fibroin (silk) material have broad applications in textiles, biomedical materials and other industrial materials. It is economical to incorporate nanoparticles to the biosynthesis of silk fibroin by adding them to silkworm larval diets. This strategy may result in the rapid stable production of modified silk. Glucose-coated silver nanoparticles (AgNPs) were used to improve the AgNPs' biocompatibility, and the AgNPs were efficiently incorporated into silk by feeding. Larvae fed with AgNPs produced silk with significantly improved antibacterial properties and altered silk secondary structures. Both positive and negative effects on the growth and synthesis of silk proteins were observed after different AgNPs doses. Larvae feeding with low concentration of 0.02% and medium 0.20% AgNPs have greater transfer efficiencies of AgNPs to silk compared with feeding high concentration of 2.00% AgNPs. In addition, the elongation and tensile strength of the produced silk fibers were also significantly increased, with greater mammalian cell compatibility. The appropriate AgNPs concentration in the diet of silkworms can promote the synthesis of silk proteins, enhance their mechanical properties, improve their antibacterial property and inhibit the presence of Gram-negative bacteria.

Herein we present a general and turn-on strategy for enzymatic bioassays on the basis of redox state dependent emission of gold nanoclusters (AuNCs). The photoluminescence of AuNCs was quenched obviously by the oxidative ferricyanide while unaffected by its corresponding reduced state, i.e., ferrocyanide. The distinctive quenching abilities for AuNCs by the redox couple (ferricyanide/ferrocyanide) enabled their utility as new fluorescent sensing platforms to detect redox-related phenomena. The proposed protocols were conducted by using the model oxidoreductases of glucose oxidase (GOx) and the enzyme cascade of lactate dehydrogenase (LDH)/diaphorase to catalytically convert ferricyanide to ferrocyanide, which switched on fluorescence of the detection systems. The detection limit for glucose and lactate was found to be as low as 0.12 and 0.09 μM, respectively. This work features the first use of the redox couple of ferricyanide/ferrocyanide in fluorescent bioanalysis, which enables versatile, signal on and highly sensitive/selective detections as compared to the state of the art fluorescently enzymatic sensing platforms. Importantly, considering the significance of ferricyanide/ferrocyanide involves in numerous other oxidoreductases mediated biocatalysis, this protocol has wide versatility that enables combination with oxidoreductases related reactions for biosensing., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In addition to superior enzyme-mimicking abilities, nanozymes also have intrinsic physicochemical properties. Integrating the enzyme-like activities and tunable physicochemical properties into a single nanoparticle is a promising strategy for versatile nanozyme design and application. Herein, a composite nanozyme in which Au nanoparticles are encapsulated by Au nanoclusters (AuNP@AuNCs) is presented. By integrating the peroxidase-mimicking ability of fluorescent Au NCs with the glucose oxidase-like activity of Au NPs, the composite nanozyme realized cascade assay of glucose without the aid of external indicators. Compared to traditional multistep colorimetric methods, the analytical process was highly simplified by using the self-responsive nanozyme. This synthetic strategy provided valuable insights into exploring talented nanozymes for sensing diverse targets., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Searching for vaccines (antigen and adjuvant) with easy preparation and strong T-cell response are crucial for antitumor immunity. In this work, to design lymphoseek-inspired vaccine possessing the abilities of promoting vaccine internalization and enhancing CD8 + T-cell responses, a simple multicomponent strategy is successfully utilized to fabricate lymph node and dendritic cell dual-targeting glycoadjuvant@AuNPs in one pot, where three different components, catechol-containing glycopolymer, HAuCl 4 , and amine-terminal CpG (CpG-NH 2 ) can react in a single step to generate target adjuvant. It is found that hetero-glycoadjuvant@AuNPs could increase adjuvant internalization and enhance the activation of bone-marrow-derived dendritic cells. Critically, lymphoseek-inspired vaccine potentiates antigen-specific CD8 + T-cell immune responses., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this study, we have investigated the structural and optical properties of nanoconjugates (NJs) consisting of phase pure zinc oxide (ZnO) nanoparticles (NPs) with glucose biomolecules. All NJs were fabricated using a standard biochemical synthesis process. Structural, optical, vibrational, and biochemical interface properties of nano-bio composites are probed by different complementary characterization techniques. The XRD patterns of the NPs and NJs illustrate a highly phase pure ZnO structure. A visible green emission in the photoluminescence spectrum, mainly associated with the oxygen vacancies on the surface of ZnO nanostructure, is significantly reduced by the incorporation of glucose biomolecules. The strong binding interaction of glucose biomolecule on the surface of ZnO NPs results in the reduction in green-yellow-orange emission intensities. The interaction of glucose molecules modifies oxygen vacancies by capturing free electrons from the ZnO surface region. Significant changes in the peak intensity and relative peak position of some of the glucose and ZnO NPs in Raman spectra refer to the direct binding between these two nano- and bio-components. In the X-ray photoelectron spectroscopy, the binding energy of O 1s core level in NJs increases from 531 eV (O 1s core level position for ZnO) and the increment is more with higher initial glucose concentration in the solution during synthesis. This study serves as a promising platform for the development of new kinds of NJs and investigation of their interfacial properties which can take the frontier forward for integration and multifunctionality.

In this paper, a highly sensitive plasmonic enzyme-linked immunosorbent assay (pELISA) was developed for the naked-eye detection of fumonisin B 1 (FB 1 ). Glucose oxidase (GOx) was used as an alternative to horseradish peroxidase as the carrier of the competing antigen. GOx catalyzed the oxidation of glucose to produce hydrogen peroxide, which acted as a reducing agent to reduce Au 3+ to Au on the surface of gold seeds (5 nm), This reaction led to a color change in the solution from colorless to purple, which was observable to the naked eye. Various parameters that could influence the detection performance of pELISA were investigated. The developed method exhibited a considerably high sensitivity for FB 1 qualitative naked-eye detection, with a visible cut-off limit of 1.25 ng/mL. Moreover, the proposed pELISA showed a good linear range of 0.31-10 ng/mL with a half maximal inhibitory concentration (IC 50 ) of 1.86 ng/mL, which was approximately 13-fold lower than that of a horseradish peroxidase- (HRP)-based conventional ELISA. Meanwhile, the proposed method was highly specific and accurate. In summary, the new pELISA exhibited acceptable accuracy and precision for sensitive naked-eye detection of FB 1 in maize samples and can be applied for the detection of other chemical contaminants., Competing Interests: The authors declare no conflict of interest.

Nitrogen-doped graphene quantum dots (N-GQDs) were prepared from dicyandiamide and then used as both an electrochemiluminescence (ECL) emitter and a reductant to produce gold nanoparticles (Au-N-GQDs) on their surface without using any reagent. In order to avoid resonance energy transfer, the Au-N-GQDs were stabilized with chitosan. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), UV-vis spectroscopy (UV-vis) and ECL methods were used to characterize the nanocomposite. The materials was placed on a glassy carbon electrode (GCE), and the ECL signals are found to be strongly quenched by hydrogen peroxide that is enzymatically produced by oxidation of glucose. With the applied typical potential of -1.7 V, the ECL of the Au-N-GQDs modified GCE decreases linearly in the 10 nM to 5.0 μM glucose concentration range, and the lower detection limit is 3.3 nM. The influence of H 2 O 2 to the signal has been discussed and a possible mechanism has been presented. Graphical abstract Schematic presentation of the reduction of gold nanoparticles with nitrogen-droped graphene quantum dots (N-GQDs) to form Au-N-GQDs. They were used to detect glucose by electrochemiluminescence through a signal off strategy.

Cancer stem-like cells (CSCs) treatment is a plausible strategy for enhanced cancer therapy. Here we report a glucose-installed sub-50-nm nanocarrier for the targeted delivery of small interfering RNA (siRNA) to CSCs through selective recognition of the glucose ligand to the glucose transporter 1 (GLUT1) overexpressed on the CSC surface. The siRNA nanocarrier was constructed via a two-step assembling process. First, a glucose-installed poly(ethylene glycol)-block-poly(l-lysine) modified with lipoic acid (LA) at the ω-end (Glu-PEG-PLL-LA) was associated with a single siRNA to form a unimer polyion complex (uPIC). Second, a 20 nm gold nanoparticle (AuNP) was decorated with ~65 uPICs through AuS bonding. The glucose-installed targeted nanoparticles (Glu-NPs) exhibited higher cellular uptake of siRNA payloads in a spheroid breast cancer (MBA-MB-231) cell culture compared with glucose-unconjugated control nanoparticles (MeO-NPs). Notably, the Glu-NPs became more efficiently internalized into the CSC fraction, which was defined by aldehyde dehydrogenase (ALDH) activity assay, than the other fractions, probably due to the higher GLUT1 expression level on the CSCs. The Glu-NPs elicited significantly enhanced gene silencing in a CSC-rich orthotopic MDA-MB-231 tumor tissue following systemic administration to tumor-bearing mice. Ultimately, the repeated administrations of polo-like kinase 1 (PLK1) siRNA-loaded Glu-NPs significantly suppressed the growth of orthotopic MDA-MB-231 tumors. These results demonstrate that Glu-NP is a promising nanocarrier design for CSC-targeted cancer treatment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This study reports a novel hollow Cu 2 O@Cu 1.8 S material used as a catalyst for enzyme free glucose detection. Cu 2 O@Cu 1.8 S is successfully synthesized by a facile in-situ growth method. The obtained Cu 2 O@Cu 1.8 S exhibits a hollow structure with a Cu 1.8 S rich surface. Compared to Cu 2 O spheres, electrochemical results reveal that the Cu 2 O@Cu 1.8 S material exhibits a much higher catalytic activity toward glucose oxidation due to synergistic effect between Cu 2 O and Cu 1.8 S. The as-prepared Cu 2 O@Cu 1.8 S produces a high sensitivity, a fast sensing response, a wide linear range in concentrations of 1-1000 μM, and an excellent selectivity, thus prove to be a promising catalyst for enzyme free glucose detection., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In this study, the effect of inter-enzyme steric hindrance that occurs during enzyme immobilization on the electrode, on direct electrical communications of enzyme with electrode was investigated via nano-patterning of enzymes on the electrode. Here, the nano-patterning of enzymes was achieved through the combination of DET-capable enzyme that was produced via fusion of site-specific gold binding peptide (GBP) to catalytic subunit of enzyme and gold nanoparticle (AuNP) array with highly tunable dimensions of AuNPs, resulting in spatially controllable enzyme-electrode. The nano-scale spatial control between immobilized enzymes on the highly tuned AuNPs shows different DET efficiency across the enzyme-electrode interface, showing 18.47% of maximum electron recovery which is 3.2-fold enhanced electron recovery efficiency compared to spatially non-controlled enzymes on the electrode where showed 5.7% of electron recovery. The result affirms that inter-enzyme interaction is a significant parameter that decides the enzyme-electrode performance., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In this work, an enzymatic sensor, based on a bionanocomposite film consisting of a polyelectrolyte complex (PEC) (Chitosan/kappa-carrageenan) doped with gold nanoparticles (AuNPs) encapsulating glucose oxidase (GOD) deposited on a gold electrode (Au) for glucose sensing, is described. Using the electrocatalytic synergy of AuNPs and GOD as a model of enzyme, the variation of the current (µA) as a function of the log of the glucose concentration (log [glucose]), shows three times higher sensitivity for the modified electrode (283.9) compared to that of the PEC/GOD modified electrode (93.7), with a detection limit of about 5 µM and a linearity range between 10 µM and 7 mM. The response of the PEC/AuNPs/GOD based biosensor also presents good reproducibility, stability, and negligible interfering effects from ascorbic acid, uric acid, urea, and creatinine. The applicability of the PEC/AuNPs/GOD based biosensor was tested in glucose-spiked saliva samples and acceptable recovery rates were obtained.

Thermosensitive glucose-functionalized glycopolymers grafted gold nanoparticles (Glyco@GNPs) with good colloidal stability and thermosensitive in aqueous solution were fabricated by reversible addition-fragmentation chain transfer (RAFT) mediated one-pot synthesis. The formation of core-shell morphology with about a 60 nm gold core in diameter and a glycopolymer shell of about 80 nm in thickness was indicated by transmission electron microscopy (TEM). The recognition ability of the Glyco@GNPs toward lectin concannavalin A (Con A) was verified by ultraviolet-visible spectroscopy and dynamic light scattering (DLS). The good cytocompatibility of the glycopolymers and Glyco@GNPs was proven by MTT assay on L-929 cells. Glyco@GNPs could effectively inhibit hepatoma cells SMMC-7721 growth after recognizing Con A was also proved by MTT assay and flow cytometry assay., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Aim: To elucidate the interactions, uptake mechanisms and cytotoxicity profile of glucose-functionalized gold nanoparticles (2GF-GNPs), for expanding and advancing the recently proposed technology of metabolic-based cancer detection to a variety of cancer diseases., Methods: Several cell types with different metabolic features were used to assess the involvement of GLUT-1 and different endocytosis pathways in 2GF-GNP uptake, and the cytotoxicity profile of 2GF-GNPs., Results: Cellular uptake of 2GF-GNP strongly correlated with GLUT-1 surface expression, and occurred mainly through clathrin-mediated endocytosis. 2GF-GNPs showed no toxic effect on cell cycle and proliferation., Conclusion: These findings promote development of metabolic-based cancer detection technologies, and suggest that 2GF-GNPs may enable specific cancer detection in a wide range of tumors characterized by high GLUT-1 expression.

Designing high-efficiency electrocatalysts for glucose concentration detection plays a pivotal role in developing various non-enzymatic glucose detection devices. Herein, we have successfully designed and synthesized various cobalt nitrides (Co 4 N) by using different weak bases (i.e. hexamethylenetetramine (HMT), urea, and ammonium hydroxide (AH)) through nitridation treatment in ammonia (NH 3 ) atmosphere. Physical characterization results demonstrate that Co 4 N-NSs (nanosheets) with vast meso/macropores and large BET surface are successfully constructed once adding carbon paper and HMT into precursors. As the synergistic effect of metallic character of Co 4 N phase , excellent electroconductibility of pyrolytic carbon, and large surface area, Co 4 N-NSs surfaces can form more Co 4+ active sites in electrochemical reaction processes. Meanwhile, the abundant meso/macroporous structures constructed in Co 4 N-NSs further promoted its mass transfer ability. Benefitting from the above mentioned advantages, Co 4 N-NSs therefore exhibit more excellent glucose oxidation ability than another three control samples (i.e. Co 4 N-HMT, Co 4 N-Urea and Co 4 N-AH). When used for glucose detection, the optimal Co 4 N-NSs display excellent detection parameters as well, such as: a wide linear range of 0.6-10.0mM, a large sensitivity of 1137.2uAcm -2 mM -1 glucose, a low detection limit of 0.1µM, a small response time of 1.7s, good reproducibility and stability, and the excellent anti-interference to other electroactive molecules and Cl - . Upon utilized for measuring glucose concentrations in human blood serum samples, the detection results on Co 4 N-NSs are accurate and satisfying as well. This work opens a new possibility for boosting electrochemical catalysis abilities of Co 4 N samples by the structure design., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The glucose metabolism rate in cancer cells is a crucial piece of information for the cancer aggressiveness. A feasible method to monitor processes of oncogenic mutations has been demonstrated in this work. The fluorescent gold nanoclusters conjugated with glucose (glucose-AuNCs) were successfully synthesized as a cancer-targeting probe for glucose transporters (Gluts) overexpressed by U-87 MG cancer cells, which can be observed under confocal microscopy. The structural and optical characterizations of fluorescent glucose-AuNCs were confirmed by transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). The MTT assay exhibited the high biocompatibility of water-soluble glucose-AuNCs for further biomedical applications. The glucose metabolic cleavage of glucose-AuNCs by glycolytic enzymes from U-87 MG cancer cell was measured by fluorescence change of glucose-AuNCs. The fluorescence change based on the integrated area under fluorescence spectra ( A t ) of glucose-AuNCs was plotted as a function of different reaction time ( t) with glycolytic enzymes. The fitted curve of A t versus t showed the first-order kinetics to explain the mechanism of glucose metabolic cleavage rate of glucose-AuNCs by glycolytic enzymes. The rate constant k could be utilized to determine the glucose metabolism rate of glucose-AuNCs for the quantitative analysis of cancer aggressiveness. Our work provides a practical application of target-specific glucose-AuNCs as a fluorescence probe to analyze the glucose metabolism in Gluts overexpressed cancer cells.

The expression levels of glycans on the surfaces of cancer and normal cells show different, however, this difference is not noticeable enough to distinguish them directly. So, herein, based on the targeted molecular recognition of the glycans on cell surfaces by 4-mercaptophenyl boronic acid (MPBA), a novel surface-enhanced Raman scattering (SERS) nanoprobe (glucose-MPBA@AgNPs) was prepared by inducing controllable assembly of MPBA decorated Ag nanoparticles (MPBA@AgNPs) in a certain level via the bridge of glucose to amplify such a limited difference in SERS measurements. On the basis of the aggregation-induced 3D SERS hot spot effect, this multi-particle nanoprobe possesses over 10 times stronger SERS enhancement ability than the individual MPBA@AgNPs. As the different sialic acid (SA) expression on the surfaces of cancer and normal cells led to the different accumulation of glucose-MPBA@AgNPs, the results we obtained (mean intensities recorded from five cells) indicate the SA amounts on two kinds of cells can provide 5-7 times signal contrast grade in SERS band intensities (P < 0.001). Compared with the monodispersed nanoprobe, our developed nanoprobe amplifies the SA expression difference on cell surfaces and supports high sensitivity for cancer cell recognition, which might be useful in providing highly effective recognition of the edges of tumor tissues in clinic field., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Glycan-lectin interactions are commonly observed in nature. Analytical methods, which are used to detect lectins that rely on the use of glycan ligand-modified nanoprobes as affinity probes, have been developed. Most of the existing methods are focused on the use of synthetic glycan ligands. Nevertheless, naturally available glycoproteins, such as ovalbumin in chicken egg whites, are good sources for fabricating glycan-immobilized nanoprobes. In this study, we generated functionalized gold nanoparticles (Au NPs) from a one-pot reaction by reacting chicken egg white (cew) proteins with aqueous tetrachloroaurate. The generated Au@cew NPs are mainly encapsulated by ovalbumin, in which the surface is decorated by abundant hybrid mannose and Galβ(1→4)GlcNAc-terminated glycan ligands. Thus, the generated Au@cew NPs containing hybrid mannose and Galβ(1→4)GlcNAc have the capability to selectively bind with their corresponding lectins. Lectins including concanavalin A, banana lectin, and ricin B that have binding moieties toward specific sugars were used as the model samples. Our results showed that the generated AuNPs can be used as multiplex affinity probes for these model lectins. Lectins can be selectively released from the Au@cew NP-lectin conjugates by using specific sugars, such as mannose, glucose, and β-lactose, as the releasing agents to release specific lectins from the conjugates. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was used as the tool to characterize the released species from the nanoprobes. The limit of detection of these model lectins using the current approach was low (in nM). The feasibility of using the Au@cew NP-based affinity MALDI-MS to selectively detect specific lectins from complex samples was also demonstrated., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This work describes the development and evaluation of a new electrochemical platform based on the sustainable generation of gold-nanoparticles on paper-based gold-sputtered electrodes. The disposable porous paper electrode is combined with screen-printed electrodes for ensuring a precise electrogeneration of nanoparticles and also for the evaluation of these simple, versatile and low-cost microfluidic devices. Two types of chromatographic paper with different thicknesses have been evaluated. Paper gold working electrodes modified with gold nanoparticles were characterized by scanning electron microscopy and cyclic voltammetry using potassium ferrocyanide as a common redox probe, showing an improved electrochemical performance when compared to bare gold electrodes. The platform has been applied to the non-enzymatic determination of glucose, molecule of enormous interest. The porous gold structure made by sputtering on paper, modified with electrogenerated nanoparticles allowed precise and accurate determination of the analyte in beverages at low potential., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This study is based on the construction of an enzymatic bioanode adopting the exclusively reported layer-by-layer (LBL) assembly of Ppy-Ag-GO/ferritin (Frt)/glucose oxidase (GOx). The glassy carbon (GC) electrode was immobilised with the conducting polypyrrole (Ppy)-silver nanoparticles (Ag)-graphene oxide (GO) based biocomposite as electron transfer elevator, horse spleen ferritin (Frt) protein as electron transfer mediator and glucose oxidase (GOx) enzyme in layer by layer configuration. The fabricated bioanode exhibited good electrochemical performance with a maximum current response of 5.7mAcm -2 accompanied with biocompatibility and environmental stability because of the synergistic effect between outstanding properties of PPy, silver and GO, thereby, showing superior catalytic efficiency for the oxidation of glucose., (Copyright © 2017. Published by Elsevier B.V.)