Facile fabrication of Au-Ag alloy nanoparticles/Ag nanowires SERS substrates with bimetallic synergistic effect for ultra-sensitive detection of crystal violet and alkali blue 6B.

The bimetallic nanostructure of Au and Ag can integrate two distinct properties into a novel substrate compared to single metal nanostructures. This work presents a rapid and sensitive surface-enhanced Raman scattering (SERS) substrate for detecting illegal food additives and dyes of crystal violet (CV) and alkali blue 6B (AB 6B). Au-Ag alloy nanoparticles/Ag nanowires (Au-Ag ANPs/Ag NWs) were prepared by solid-state ionics method and vacuum thermal evaporation method at 5µA direct current electric field (DCEF), the molar ratio of Au to Ag was 1:18.34. Many 40 nm-140 nm nanoparticles regularly existed on the surface of Ag NWs with the diameters from 80 nm to 150 nm. The fractal dimension of Au-Ag ANPs/Ag NWs is 1.69 due to macroscopic dendritic structures. Compared with single Ag NWs, the prepared Au-Ag ANPs/Ag NWs substrates show superior SERS performance because of higher surface roughness, the SERS active of Ag NWs and bimetallic synergistic effect caused by Au-Ag ANPs, so the limit of detections (LOD) of Au-Ag ANPs/Ag NWs SERS substrates toward detection of CV and AB 6B were as low as 10-16mol/L and 10-9mol/L, respectively. These results indicate that Au-Ag ANPs/Ag NWs substrates can be used for rapid and sensitive detection of CV and AB 6B and have great development potential for detection of illegal food additives and hazardous substances in the fields of environmental monitoring and food safety.

Tremendously enhanced catalytic performance of Fe(III)/peroxymonosulfate process by trace Cu(II): A high-valent metals domination in organics removal.

Dissolved copper and iron ions are regarded as friendly and economic catalysts for peroxymonosulfate (PMS) activation, however, neither Cu(II) nor Fe(III) shows efficient catalytic performance because of the slow rates of Cu(II)/Cu(I) and Fe(III)/Fe(II) cycles. Innovatively, we observed a significant enhancement on the degradation of organic contaminants when Cu(II) and Fe(III) were coupled to activate PMS in borate (BA) buffer. The degradation efficiency of Rhodamine B (RhB, 20 µmol/L) reached up to 96.3% within 10 min, which was higher than the sum of individual Cu(II)- and Fe(III)- activated PMS process. Sulfate radical, hydroxyl radical and high-valent metal ions (i.e., Cu(III) and Fe(IV)) were identified as the working reactive species for RhB removal in Cu(II)/Fe(III)/PMS/BA system, while the last played a predominated role. The presence of BA dramatically facilitated the reduction of Cu(II) to Cu(I) via chelating with Cu(II) followed by Fe(III) reduction by Cu(I), resulting in enhanced PMS activation by Cu(I) and Fe(II) as well as accelerated generation of reactive species. Additionally, the strong buffering capacity of BA to stabilize the solution pH was satisfying for the pollutants degradation since a slightly alkaline environment favored the PMS activation by coupling Cu(II) and Fe(III). In a word, this work provides a brand-new insight into the outstanding PMS activation by homogeneous bimetals and an expanded application of iron-based advanced oxidation processes in alkaline conditions.

Insight into the bimetallic structure sensibility of catalytic nitrate reduction over Pd-Cu nanocrystals.

Catalytic reduction of nitrate over bimetallic catalysts has emerged as a technology for sustainable treatment of nitrate-containing groundwater. However, the structure of bimetallic has been much less investigated for catalyst optimization. Herein, two main types of Pd-Cu bimetallic nanocrystal structures, heterostructure and intermetallic, were prepared and characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that two individual Pd and Cu nanocrystals with a mixed interface exist in the heterostructure nanocrystals, while Pd and Cu atoms are uniformly distributed across the intermetallic Pd-Cu nanocrystals. The catalytic nitrate reduction experiments were carried out in a semibatch reactor under constant hydrogen flow. The nitrate conversion rate of the heterostructure Pd-Cu nanocrystals supported on α-Al2O3, γ-Al2O3, SBA-15, and XC-72R exhibited 3.82-, 6.76-, 4.28-, 2.44-fold enhancements relative to the intermetallic nanocrystals, and the nitrogen and nitrite were the main products for the heterostructure and intermetallic Pd-Cu nanocrystals, respectively. This indicates that the catalytic nitrate reduction over Pd-Cu catalyst is sensitive to the bimetallic structures of the catalysts, and heterostructure bimetallic nanocrystals exhibit better catalytic performances on both the activity and selectivity, which may provide new insights into the design and optimization of catalysts to improve catalytic activity and selectivity for nitrate reduction in water.

Smartphone-assisted colorimetric biosensor for the rapid visual detection of natural antioxidants in food samples.

Quantitative monitoring of the concentrations of epigallocatechin gallate (EGCG) and cysteine (Cys) is of great significance for promoting human health. In this study, iron/aluminum bimetallic MOF material MIL-53 (Fe, Al) was rapidly prepared under room temperature using a co-precipitation method, followed by investigating the peroxidase-like (POD-like) activity of MIL-53(Fe, Al) using 3,3',5,5'-tetramethylbenzidine (TMB) as a chromogenic substrate. The results showed that the Michaelis -Menten constants of TMB and H2O2 as substrates were 0.167 mM and 0.108 mM, respectively. A colorimetric sensing platform for detecting EGCG and Cys was developed and successfully applied for analysis and quantitative detection using a smartphone. The linear detection range for EGCG was 15∼80 µM (R2=0.994) and for Cys was 7∼95 µM (R2=0.998). The limits of detection (LOD) were 0.719 µM and 0.363 µM for EGCG and Cys, respectively. This work provides a new and cost-effective approach for the real-time analysis of catechins and amino acids.

Why Colloidal Syntheses of Bimetallic Nanoparticles Cannot be Generalized.

Introducing one general synthesis to form bimetallic nanoparticles (NPs) could accelerate the discovery of NPs for promising energy applications. Although colloidal syntheses can provide precise structural and morphological control of bimetallic NPs, the complex chemical nature of multicomponent syntheses challenges the realization of such synthetic simplicity. Common synthetic issues are frequently ascribed to the variation in metal ion precursor reactivities and complex chemical interactions between the different metal surfaces and capping agents employed. However, no systematic studies have shown how these factors compete to ultimately assign the factor limiting the mixing and formation of bimetallic NPs. Here, we provide a parametric investigation of how the intrinsic standard reduction potentials (E0red) of the metal ions and cocapping agents influence the formation of bimetallic AuCu, AuPd, and PdCu NPs. Using a combination of in situ X-ray total scattering along with transmission electron microscopy and nuclear magnetic resonance spectroscopy, we illustrate the multifunctional role of the cocapping agents through interactions with both the metal ion precursors and NP surfaces to stabilize metastable structures. Additionally, we demonstrate how system-specific side reactions and the local metal ion coordination environment can be used to selectively tune the formation kinetics, structure, and morphology of bimetallic NPs. Ultimately, these insights show that the chemical interactions rather than the intrinsic E0red are responsible for the formation of bimetallic NPs. Broadly, these insights should aid the synthetic design of tailored multimetallic NPs.

Ultrasonically assisted fabrication of electrochemical platform for tinidazole detection.

Based on sonochemistry, green synthesis methods play an important role in the development of nanomaterials. In this work, a novel chitosan modified MnMoO4/g-C3N4 (MnMoO4/g-C3N4/CHIT) was developed using ultrasonic cell disruptor (500 W, 30 kHz) for ultra-sensitive electrochemical detection of tinidazole (TNZ) in the environment. The morphology and surface properties of the synthesized MnMoO4/g-C3N4/CHIT electrode were characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and transmission electron microscope (TEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were utilized to assess the electrochemical performance of TNZ. The results indicate that the electrochemical detection performance of TNZ is highly efficient, with a detection limit (LOD) of 3.78 nM, sensitivity of 1.320 µA·µM-1·cm-2, and a detection range of 0.1-200 µM. Additionally, the prepared electrode exhibits excellent selectivity, desirable anti-interference capability, and decent stability. MnMoO4/g-C3N4/CHIT can be successfully employed to detect TNZ in both the Songhua River and tap water, achieving good recovery rates within the range of 93.0 % to 106.6 %. Consequently, MnMoO4/g-C3N4/CHIT's simple synthesis might provide a new electrode for the sensitive, repeatable, and selective measurement of TNZ in real-time applications. Using the MnMoO4/g-C3N4/CHIT electrode can effectively monitor and detect the concentration of TNZ in environmental water, guiding the sewage treatment process and reducing the pollution level of antibiotics in the water environment.

Bimetallic FeCo-MOFs mediated Au nanorods etching for the multi-colorimetric and photothermal immunosensing of illegal additive.

With the rapid expansion of the health food industry, the scope of safety supervision has also increased. However, traditional instrument detection methods cannot meet the requirements for the rapid on-site detection. Hence, the development of a rapid, precise, and simple method for the analysis of illegal additives in health foods is of great importance. In this work, by using FeCo-MOFs as mimetic peroxidase to mediate Au nanorods (Au NRs) etching, a dual-mode immunosensor based on multi-colorimetric and photothermal signals was fabricated to detect furosemide (FUR). In multi-colorimetric channel, the localized surface plasmon resonance (LSPR) peaks of Au NRs shifted blue, resulting in multi-color changes from red to gray to blue and finally to purple. In photothermal channel, the photothermal effect of Au NRs decreased, resulting in temperature changes. In the range of 1.0 × 10-5-1.0 × 10-2 µg/mL, both LSPR peak blue shift and temperature changes were linearly correlated with the logarithm of FUR concentration, with the detection limits were 4.9 × 10-6 and 8.5 × 10-6 µg/mL, respectively. Furthermore, its concentration can be accurately and intuitively assessed through the observation of vivid colorimetric changes. This advancement offers a highly promising approach for the on-site detection of FUR, facilitating timely and efficient monitoring, thereby significantly enhancing regulatory compliance and ensuring consumer safety.

Superactivity of Bimetallic CuFeO2 Submicron Particles towards Selective Proteolysis, Depending on Their Surface Hydroxyls.

Nano bimetallic oxides as nanoproteases have the great advantages in the heterogeneous hydrolysis of proteins. Here, we report that bimetallic delafossite CuFeO2 submicron particles (CuFeO2 SMPs) display a high protease activity towards selective cleavage of peptide bond involving hydrophobic residue at 25 centidegree. CuFeO2 SMPs have excellent regeneration performance with high structural stability. The strong Lewis acidity of Fe(III) and the strong nucleophilicity of Cu(I) bound hydroxyl groups are both necessary for the high protease activity of CuFeO2 SMPs. Low-valent metal ion has a great advantage in that low-valent Cu(I) bound hydroxyl has strong nucleophilicity, resulting in promotion of protein hydrolysis via high-efficient bimetallic catalysis. This study provides evidence that the protease activity of CuFeO2 SMPs depends on metal ion-bound hydroxyls on their surface. Our findings highlight that the valence of metal ions in artificial protease and their surface hydroxyls are two important factors that determine their catalytic efficiency.

The electrochemical properties of bimetallic silver-gold nanoparticles nano film's.

Electrode modification has been one of the most active areas of interest in electrochemistry research. Hence, the investigation of the effects of chemically and electrochemically modified GCE nano-films on the NPs electrochemical properties. The electrochemistry of nano-films of Ag NPs, Au NPs and bimetallic Ag-Au (1:2) NPs of chemical citrate reduction synthesis drop coated (DCT) and electro-deposition method (EDP) are reported. The Chemically synthesized NPs were confirmed through FT-IR, UV-visible, XRD and SEM techniques while electro-deposited NPs were ascertained by double-pulsed chrono-amperometry and electrochemical impedance spectroscopy (EIS). The nano films; GCE/Ag NPs, GCE/Au NPs and GCE/Ag-Ag (1:2) NPs in 0.1 M HCl supporting electrolyte were studied via Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) techniques. Generally the DCT nano films were electrochemically superior to the EDP film in terms of current intensities and GCE/Ag-Au (1:2) NPs showed enhanced α (0.019), k s (0.01 s-1), Q (3.6 × 10-9 C), Γ (5.3 × 10-13molescm-2) and D (1.31 × 10-1 cm2s-1), indicating better physicochemical properties for possible sensing applications compared to electro-deposited GCE nano-films.

Bimetallic PdCu anchored to 3D flower-like carbon material for portable and efficient detection of glyphosate.

Glyphosate (Gly), as a widely used broad-spectrum herbicide, may lead to soil and water pollution due to its persistence in the environment. Herein, the co-reduction method was employed to anchor bimetallic PdCu onto the Ni and nitrogen-doped 3D Flower-like Carbon Materials (Ni@NC), creating a composite material (PdCu/Ni@NC) with high specific surface area and good catalytic performance. This composite was used to modify screen-printed electrodes (SPE) to develop a portable and efficient Gly detection platform. In the presence of Cl⁻, the copper active sites convert to CuCl, achieving signal amplification. Upon the addition of Gly, a competitive reaction between Cu and Gly converts CuCl into a Cu-Gly complex, resulting in a sharp decrease in the electrochemical signal. This signal drop is used to detect Gly. The bimetallic PdCu nanoparticles (NPs) endowed the sensing platform with better stability and electrochemical performance due to their synergistic effect, and their stability was simply verified by Density functional theory (DFT). The sensor demonstrates a linear detection range spanning from 1 × 10⁻¹ ³ to 1 × 10⁻5 M, with a limit of detection (LOD) of 3.72 × 10⁻¹ 4 M. The sensor demonstrated a recovery rate of 95.9 % to 104.5 % in actual samples such as water and soil, indicating its potential for practical application.

Polyvinyl alcohol/sodium alginate-based conductive hydrogels with in situ formed bimetallic zeolitic imidazolate frameworks towards soft electronics.

Bimetallic zeolitic imidazolate frameworks (BZIFs) have received enormous attention due to their unique physi-chemical properties, but are rarely reported for electrically conductive hydrogel (ECH) applications arising from low intrinsic conductivity and poor dispersion. Herein, we propose an innovative strategy to prepare highly conductive and mechanically robust ECHs by in situ growing Ni/Co-BZIFs within the polyvinyl alcohol/sodium alginate dual network (PZPS). 2-methylimidazole (MeIM) ligands copolymerize with pyrrole monomers, enhancing the electrical conductivity; meanwhile, MeIM ligands act as anchor points for in-situ formation of BZIFs, effectively avoiding phase-to-phase interfacial resistance and ensuring a uniform distribution in the hydrogel network. Due to the synergism of Ni/Co-BZIFs, the PZPS hydrogel exhibits a high areal capacitance of 630.3 mF·cm-2 at a current density of 0.5 mA·cm-2, promising for flexible energy storage devices. In addition, PZPS shows excellent mechanical strength and toughness (with an ultimate tensile strength of 405.0 kPa and a toughness of 784.2 kJ·m-3 at an elongation at break of 474.0 %), a high gauge factor of up to 4.18 over an extremely wide stress range of 0-42 kPa when used as flexible wearable strain/pressure sensors. This study provides new insights to incorporating highly conductive and uniformly dispersed ZIFs into hydrogels for flexible wearable electronics.

High-Performance Bimetallic Electrocatalysts for Hydrogen Evolution Reaction Using N-Doped Graphene-Supported N-Co6Mo6C.

Hydrogen has garnered considerable attention as a promising energy source for addressing contemporary environmental degradation and energy scarcity challenges. Electrocatalytic water splitting for hydrogen production has emerged as an environmentally friendly and versatile method, offering high purity. However, the development of cost-effective electrocatalytic catalysts using abundant and inexpensive materials is crucial. In this study, we successfully synthesized nitrogen-doped Co6Mo6C supported on nitrogen-doped graphene (N-Co6Mo6C/NC). The catalyst exhibited high performance and durability in alkaline electrolytes (1.0 M KOH) for hydrogen evolution, showcasing an overpotential of 185 mV at a current density of 100 mA cm-2 and a Tafel slope of 80 mV dec-1. These findings present a novel avenue for the fabrication of efficient bimetallic carbide catalysts.

Bimetallic catalyst system for the degradation of PCBs in sediments.

In this paper, we report the successful application of a patent-pending reduced bimetallic nanoparticle catalytic system developed for the remediation of polychlorinated biphenyl (PCB)-contaminated sediment and aquatic media. The formation of bimetallic nanoparticles associated with the granular activated carbon (GAC) were confirmed by high-resolution transmission electron microscopy. X-ray photoelectron spectroscopy showed the presence of the bimetallic matrix in reduced, albeit mixed, states. In the degradation studies, the bimetallic nanoparticles were deposited on a GAC substrate and utilized to treat both a surrogate PCB, 2-Chlorobiphenyl (2-CBP) in water and contaminated bottom-river sediments collected from a site with mixed-congener PCB contamination. The degradation studies on non-degassed water contaminated with 2-CBP at room temperature showed a high yield of 2-CBP degradation to biphenyl and phenol. Results from the bottom-river sediments contaminated with PCBs (tested in laboratory environment at ambient temperature and atmospheric conditions, not degassed) have indicated the bimetallic catalyst has great promise for remedial application in sediment and aquatic media. Results illustrate that this newly-developed and patent-pending catalytic system degrades PCBs through stepwise dichlorination, with expected byproducts such as biphenyl and phenol leading to mineralization of the PCBs.

Cu-Ni Bimetallic Nanowires with Various Structures Originating from Ni Reduction Kinetics.

Bimetallic nanowires play important roles in the fields of electronics and mechanics. However, their structure types and morphological control methods are limited, especially for systems with low lattice mismatch. Herein, for a Cu-Ni bimetallic system with lattice mismatch ratio less than 2.5%, a novel preparation approach of various Cu-Ni nanowires dominated by Ni(II) reduction kinetics is presented. With the increase of Ni(II) reduction rate, the core-shell Cu@Ni straight nanowires, the asymmetric Cu-Ni nanocurves, and asymmetric Cu-Ni nanocoils can be prepared, respectively. The formation of Cu-Ni nanowires with different structures can be divided into the growth of Cu nanowires and the deposition of Ni. The regulatory effects were revealed by establishing a kinetic model for Ni(II) reduction. For the novel Cu-Ni asymmetrically distributed nanocurves and nanocoils, the formation mechanism was proposed by considering the Cu nanowire bending due to the rearrangement of surface ligand and bending-induced symmetry breaking of Ni(II) reduction.

Hydrodeoxygenation of Isoeugenol-derived Model Compound over Carbon-supported Pt and Pt-SnS Catalysts for the Production of Sustainable Jet Fuel.

This study focuses on the sustainable production of bio-jet fuel through the catalytic hydrodeoxygenation (HDO) of isoeugenol (IE). Properties of two spraying synthesis methods (in situ and ex situ metal doping) with different platinum (Pt) loading percentages. The catalyst was characterised using various techniques such as XAS, X-ray photoelectron spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FESEM) and thermogravimetric analysis. The HRTEM and FESEM results show the successful preparation of a spherical nanoparticle doped over activated carbon, and Pt was dispersed on the outer shell of the particles. The catalytic HDO of IE showed a high yield and conversion as follows: IE conversion of 100%, liquid-phase mass balance of 95.92%, dihydroeugenol conversion of 99.32%, propylcyclohexane yield of 88.94% and HYD yield of 76.19%. Moreover, the catalyst exhibited high reusability with low metal leaching and high coke resistance for 10 cycles. The catalyst was evaluated in a continuous flow reactor for 100 h at different reaction temperatures, and interestingly, the catalyst showed low deactivation with a high half-time.

Colloidal Bimetallic RuNi Particles and their Behaviour in Catalytic Quinoline Hydrogenation.

Colloidal metal nanoparticles exhibit interesting catalytic properties for the hydrogenation of (hetero)arenes. Catalysts based on precious metals, such as Ru and Rh, proceed efficiently under mild reaction conditions. In contrast, heterogeneous catalysts based on earth-abundant metals can selectively hydrogenate (hetero)arenes but require harsher reaction conditions. Bimetallic catalysts that combine precious and earth-abundant metals are interesting materials to mitigate the drawbacks of each component. To this end, RuNi nanoparticles bearing a phosphine ligand were prepared through the decomposition of [Ru(η4-C8H12)(η6-C8H10)] and [Ni(η4-C8H12)2] by H2 at 85°C. Wide angle X-ray scattering confirmed a bimetallic segregated structure, with Ni predominantly on the surface. Spectroscopic analyses revealed that the phosphine ligand coordinated to the surface of both metals, suggesting, as well, a partial Ni shell covering the Ru core. The RuNi-based nanomaterials were used as catalysts in the hydrogenation of quinoline to assess the impact of the metallic composition and of the stabilizing agent on their catalytic performance.

Bimetallic Coupling Strategy Modulating Electronic Construction to Accelerate Sulfur Redox Reaction Kinetics for High-Energy Flexible Li-S Batteries.

Lithium-sulfur (Li-S) batteries are considered the most promising energy storage battery due to their low cost and high theoretical energy density. However, the low utilization rate of sulfur and slow redox kinetics have seriously limited the development of Li-S batteries. Herein, the electronic state modulation of metal selenides induced by the bi-metallic coupling strategy is reported to enhance the redox reaction kinetics and sulfur utilization, thereby improving the electrochemical performance of Li-S batteries. Theoretical calculations reveal that the electronic structure can be modulated by Ni-Co coupling, thus lowering the conversion barrier of lithium polysulfides (LiPSs) and Li+, and the synergistic interaction between NiCoSe nanoparticles and nitrogen-doped porous carbon (NPC) is facilitating to enhance electron transport and ion transfer kinetics of the NiCoSe@NPC-S electrodes. As a result, the assembled Li-S batteries based on NiCoSe@NPC-S exhibit high capacities (1020 mAh g-1 at 1 C) and stable cycle performance (80.37% capacity retention after 500 cycles). The special structural design and bimetallic coupling strategy promote the batteries working even under lean electrolyte (7.2 µL mg-1) with a high sulfur loading (6.5 mg cm-2). The proposed bimetallic coupling strategy modulating electronic construction with N-doping porous carbon has jointly contributed the good redox reaction kinetics and high sulfur utilization.

Boosting peroxymonosulfate activation via Fe-Cu bimetallic hollow nanoreactor derived from copper smelting slag for efficient degradation of organics: The dual role of Cu.

Valorization of iron-rich metallurgical slags in the construction of Fenton-like catalysts has an appealing potential from the perspective of sustainable development. For the first time, copper smelting slag (CSS) was utilized as the precursor to synthesize hollow sea urchin-like Fe-Cu nanoreactors (Cu1.5Fe1Si) to activate peroxymonosulfate (PMS) for chlortetracycline hydrochloride (CTC) degradation. The hyper-channels and nano-sized cavities were formed in the catalysts owing to the induction and modification of Cu, not only promoting the in-situ growth of silicates and the formation of cavities due to the etching of SiO2 microspheres, but also resulting the generation of nanotubes through the distortion and rotation of the nanosheets. It was found that 100 % CTC degradation rate can be achieved within 10 min for Cu1.5Fe1Si, 75 times higher than that of Cu0Fe1Si (0.0024 up to 0.18 M-1‧min-1). The unique nanoconfined microenvironment structure could enrich reactants in the catalyst cavities, prolong the residence time of molecules, and increase the utilization efficiency of active species. Density functional theory (DFT) calculations show that Cu1.5Fe1Si has strong adsorption energy and excellent electron transport capacity for PMS, and Fe-Fe sites are mainly responsible for the activation of PMS, while Cu assists in accelerating the Fe(II)/Fe(Ⅲ) cycle and promotes the catalytic efficiency. The excellent mineralization rate (83.32 % within 10 min) and efficient treatment of CTC in consecutive trials corroborated the high activity and stability of the Cu1.5Fe1Si. This work provides a new idea for the rational design of solid waste-based eco-friendly functional materials, aiming at consolidating their practical application in advanced wastewater treatment.

Boosting the Stability of Subnanometer Pt Catalysts by the Presence of Framework Indium(III) Sites in Zeolite.

Subnanometer metal clusters show advantages over conventional metal nanoparticles in numerous catalytic reactions owing to their high percentage of exposed surface sites, abundance of under-coordinated metal sites and unique electronic structures. However, the applications of subnanometer metal clusters in high-temperature catalytic reactions (>600 °C) are still hindered, because of their low stability under harsh reaction conditions. In this work, we have developed a zeolite-confined bimetallic PtIn catalyst with exceptionally high stability against sintering. A combination of experimental and theoretical studies shows that the isolated framework In(III) species serve as the anchoring sites for Pt species, precluding the migration and sintering of Pt species in the oxidative atmosphere at ≥650 °C. The catalyst comprising subnanometer PtIn clusters exhibits long-term stability of >1000 h during a cyclic reaction-regeneration test for ethane dehydrogenation reaction.

Probing trace of intracellularly-originated hydrogen peroxide based Pt-Cd bimetallic nanozyme on an enzyme-free electrochemical sensor.

BACKGROUND: Measurement of endogenous cellular hydrogen peroxide (H2O2) can provide information on cellular status, and help to understand cellular metabolism and signaling processes, thus contributing to elucidation of disease mechanisms and new diagnostics/therapeutic approaches. RESULTS: In this work, Pt-Cd bimetallic nanozyme was successfully prepared via the solvothermal synthetic method for sensitive detection of H2O2. The synthesized Pt-Cd bimetallic nanozyme could exhibited good electrochemical activity. Then, the materials were analyzed for the electrochemical properties and catalytic properties of H2O2 by cyclic voltammetry and chronoamperometry, respectively. Results indicated that the synthesized nanozyme had superior sensitivity (295 µA⸳mM-1⸳cm-2) and selectivity toward H2O2 with a detection limit of 0.21 µM. Further, the Pt-Cd bimetallic nanozyme displayed good electrochemical properties compared to platinum catalysts alone. The application was extended to determine the produced H2O2 from human hepatocellular carcinoma cells (HepG2) and normal hepatocyte (LO2) samples after ascorbic acid stimulation, thus enabling the early warning of cellular carcinogenesis. SIGNIFICANCE: This strategy promises simple, rapid, inexpensive and effective electrochemical sensing and provides a new pathway for the synthesis of bimetallic nanozymes to construct an electrochemical sensor for the sensitive detection of H2O2.