Prussian Blue Analogues Research Articles

Portable Hydrogel Kits Made with Bimetallic Nanozymes for Point-of-Care Testing of Perfluorooctanesulfonate.

Perfluorooctanesulfonate (PFOS), an emerging organic contaminant, necessitates robust on-site detection strategies to safeguard human health and ecological balance. This study introduces a novel point-of-care testing (POCT) platform, combining a hydrogel kit with nanozymes and smartphone technology, for the highly sensitive detection of PFOS. The strategy utilizes copper-substituted cobalt-based Prussian blue analogue nanoboxes (CuCo-PBA NBs), which exhibit intricate hollow structures and remarkable peroxidase-like catalytic activity, efficiently catalyzing the oxidation of chromogenic substrates with hydrogen peroxide (H2O2). Density functional theory calculations elucidate the adsorption dynamics of H2O2 on CuCo-PBA NBs, identifying the factors that improve the catalytic efficiency. The colorimetric POCT platform, integrating the hydrogel kit with a smartphone interface, demonstrates practical utility and achieves a detection limit of 1.43 × 10-8 mol L-1 for PFOS. This research not only presents a new nanozyme design for PFOS detection in diverse matrices, such as lake water, whole blood, urine, and milk, but also paves the way for developing a portable and efficient POCT platform for a variety of emerging contaminants.

La doping of CoFe Prussian blue analogs for improved catalytic activity toward norfloxacin degradation

Prussian blue analogs (PBAs) are promising catalysts in heterogeneous oxidation processes. The catalytic activity of PBAs relies on exposed crystal facets and accessible active sites on the PBA framework. Employing a heteroatom doping strategy using a rare earth element (La), we regulated the crystal structure and optimized the catalytic activity of CoFe PBA for peroxymonosulfate (PMS)-driven degradation of the antibiotic norfloxacin (NOR). The La atoms were mainly doped in the interstitial sites of the CoFe PBA cubic lattices, without affecting the electron distributions of Co and Fe metals or the face-centered cubic crystal phase of the coordination skeleton. La doping dominated the (111) and (100) as the main exposed facets of CoFeLa PBA, increasing the affinity of CoFeLa PBAs for PMS adsorption due to the higher surface energy of the two facets. Consequently, the activation energy considerably declined from 77.57 kJ/mol in CoFe PBA to 51.66 kJ/mol in CoFeLa PBA and the catalytic activity for PMS-driven NOR degradation was largely improved, which can reach 76.4 % removal of NOR within 15 min, with an increased initial rate constant k of 0.095 min−1. 1O2 was proven as the main reactive specie responsible for NOR degradation in the PMS/CoFeLa system, and O2·− and SO4·− were verified as the important intermediates to generate 1O2. Thus, La doping can effectively enhance the catalytic performance of PBA-based catalysts for organic pollutant removal.

Precise electronically modulated Mn doped nickel iron phosphate with P, N codoped carbon decorated P-doped carbonized bacterial cellulose for efficient electrocatalytic glucose conversion coupled with H2 generation

Biomass electrocatalytic-conversion coupled with hydrogen generation exhibits low energy consumption, efficient hydrogen production and green syntheses of value-added chemicals. However, constructing electrocatalysts with precise electronic modulation and structures for efficient biomass electrocatalytic conversion coupled hydrogen production remains challenging. Herein, a bacterial cellulose substrate was combined in situ with a Mn-doped NiFe Prussian blue analogue (PBA) precursor, and one-step carbonization-phosphorylation was developed for the preparation of Mn-doped nickel iron phosphate (MNFP) embedded in a P, N codoped carbon (PNC) substrate grown directly on P-doped carbonized bacterial cellulose (MNFP-PNC/PCBC). Benefiting from the three-dimensional network structure of P-doped carbonized bacterial cellulose (PCBC) and atomic doping, MNFP-PNC/PCBC exhibited an optimized electronic structure, abundant active sites and excellent electrical conductivity. Therefore, the voltages required with hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and glucose electrocatalytic-conversion (GCR) to drive a current density of 50 mA cm−2 were 0.214, 1.5, and 1.34 V, respectively. Moreover, the required cell voltage of the novel electrolyser containing MNFP-PNC/PCBC as electrodes can be further reduced to 1.55 V at 50 mA cm−2 compared to overall water splitting, resulting in more than 8-time improvement in hydrogen production efficiency and production of value-added formate. This work provides a unique approach for electrocatalytic-conversion of biomass coupled with electrocatalytic hydrogen generation.

Prussian blue analogue nanospheres immobilized on self-floating biochar for micropollutant degradation via photo-Fenton process

Fe-Co Prussian blue analogue (PBA) nanospheres were immobilized on biochar (PBA-on-biochar) to remove contaminants via photo-Fenton process. The loading weight of FeCo PBA on biochar increased with increasing PBA aging temperature and time. The PBA exhibited efficient chloroquine phosphate (CQ) degradation under both LED light and sunlight, where OH and 1O2 dominated the oxidation. The CQ degradation was slightly affected by pH value (3.5–9.5) and co-existing anions like SO42−, Cl− and NO3–. The application potential of the PBA-on-biochar was evaluated in a continuous reaction device. Theoretical calculation revealed the dominant role of Fe sites in PBA for H2O2 activation. The degradation pathway was proposed based on nine intermediate products. Also, the excellent photo-Fenton activity and good floatability enable PBA-on-biochar to be efficient in inhibiting the activity of Microcystis aeruginosa under sunlight. The results implied that PBA-on-biochar is applicable for fast micropollutant oxidation from water.

Regulating core-shell interfacial interaction by oxygen bridging for enhancing electrochemical performance

It is crucial to design core-shell materials with interfacial interaction, which enhances their electrical conductivity, structural stability, and facilitates efficient charge transfer at the interface. In this study, two core-shell electrodes NC-O-PBA (NC: nickel cobalt layered double hydroxides, O-bridged core-shell materials) and LCCH@Ni(OH)2@PBA (LCCH: linear cobalt carbonate hydroxides, PBA: prussian blue analogs) were fabricated via interfacial contrast strategy to investigate the optimization function of oxygen at core-shell interface. Results show that as-prepared NC-O-PBA with high oxygen content creates an ideal condition for the formation of oxygen bridging. Moreover, the NC-O-PBA promotes a strong bond cooperation between core (NiCo-LDH) and shell (NiCo PBAs). The unit in PBAs can partly coordinate with the oxygen (from hydroxyl groups and interlayer ions in LDH), thus forming a strong interfacial coordination bonding between LDH and PBAs (Ni/Co(LDH)-O-CN(PBAs) or Ni/Co(LDH)-O-Ni/Co(PBAs)). Subsequently, NC-O-PBA electrode presents a high capacity of 1040.6 F g−1 at 1 A g−1 and a retention rate of 87.5% at 1500 cycles of 3 A g−1, much higher than LCCH@Ni(OH)2@PBA (462.4 F g−1 and 41.26%). Finally, in-situ Raman results demonstrated the enhanced Faraday redox reaction of NC-O-PBA. This interfacial contrast strategy and oxygen-bridged approach provide a novel idea for the development of high-performance core-shell electrode materials and facilitate deeper insights into mechanism.

Co-Fe bimetallic oxides derived from Prussian blue analogs to activate peracetic acid for eliminating sulfamethazine: Contribution and identification of radical species

Peracetic acid (PAA), as a disinfectant with powerful oxidation and exceptional antimicrobial efficiency, has gained considerable attention for its application in advanced oxidation processes (AOPs). However, leaching of metal ions and low recovery efficiency limited the application of heterogeneous AOPs. Herein, we synthesized a CoFe bimetallic oxide (Co-Fe-O) derived from Prussian blue analogs to serve as an activator for PAA, efficiently eliminating sulfamethazine (SMZ) in a wide pH range (5–9). Electron paramagnetic resonance and quenching test revealed the coexistence of radical species in the system, and R-O· were the main factors of SMZ elimination. The steady-state model evaluation showed that 3.1 × 10−14 M R-O· and 2.05 × 10−14 M ·OH existed in the system. CoFe bimetallic synergies expedite the generation of radical species. Based on density functional theory, the aniline ring and heterocyclic ring of SMZ were regarded as the susceptible sites for radical attack and electron transfer. Furthermore, the elimination pathway of SMZ was proposed by combining the results of intermediate products. Additionally, the toxicity of SMZ and intermediates as well as the reaction conditions, water matrices, stability, and oxidation capacity of Co-Fe-O/PAA were subjected to evaluation. Results indicate that the Co-Fe-O/PAA system has significant application potential in the elimination of micropollutants.

Rational design of Core-Shell heterostructured CoFe@NiFe Prussian blue analogues for efficient capacitive deionization

Rational design of stable and high-capacity faradaic electrode materials is crucial for enhancing the desalination performance of hybrid capacitive deionization (HCDI). In this work, to fully exploit the advantages of high-capacity CoFe Prussian blue analogs (PBA) and structurally stable NiFe PBA, a core–shell heterostructured CoFe@NiFe PBA is successfully synthesized by a two-step co-precipitation method. The construction of the core–shell heterostructure not only suppresses dissolution of the CoFe PBA core, but also facilitates fast charge transfer and efficient ion diffusion during Na+ ions insertion/extraction. With an optimal NiFe PBA shell thickness of 30 nm, the core–shell structured PBA electrode demonstrates outstanding cycling performance with a capacity retention of 72.6 % over 10,000 charge/discharge cycles. Moreover, when utilized as the cathode material in HCDI, the core–shell heterostructured PBA exhibits intriguing desalination performance, including a high desalination capacity of 49 mg g−1 and excellent desalination stability over 200 cycles (77.7 %). This paper presents a straightforward strategy for designing core–shell heterostructured PBA electrode, with the potential to advance the development of high-performance capacitive desalination.

Prussian blue analogues improves the microenvironment after spinal cord injury by regulating Zn

Mitochondrial injury, neuronal apoptosis and phenotypic transformation of macrophages are the main mechanisms of spinal cord injury. Based on the Prussian blue nanomase's strong ability to clear free radicals, the treatment of spinal cord injury with nano-zirconium (Pb–Zr) was carried out. The disease treatment strategy based on nanomaterials has excellent therapeutic effect, and Prussian blue analogs have good therapeutic properties, so the application prospects of Prussian blue analogs is broad. From the point of view of Prussian blue content, improving the presence of zirconium in the microenvironment significantly increased the activity of Prussian blue. Prussian Blue zirconium significantly improved lipopolysaccharide (LPS) and interferon (IFN-γ) induced neuronal cell (pc12 cells) and macrophage dysfunction by improving oxidative stress, inflammation, and apoptosis in the microenvironment. It can promote the recovery of motor function after spinal cord injury. In vivo experiments, it shows that Prussian blue zirconium can improve inflammation, apoptosis and oxidative stress of spinal cord tissue, promote regenerative therapy after spinal cord injury, and improve motor function. Moreover, it has been reported that high-priced Zr4+ cations can regulate the deposition and nucleation behavior of Zn2+ in high-performance zinc metal anodes. Therefore, we propose the hypothesis that Pb–Zr modulates Zn2+ be used to promote recovery from spinal cord injury. The results show that nanomaterial is beneficial in the treatment of spinal cord injury. This study provides a good prospect for the application of spinal cord injury treatment. It also provides an important feasibility for subsequent clinical conversions.

Enhancing Oxygen Evolution Reaction through In Situ Electrochemical Oxidation for the Structural Control of Co-Fe Prussian Blue Analogue

The development of exceptionally efficient catalysts for the oxygen evolution reaction (OER) and gaining a deep understanding of their activity is essential for advancing electrochemical conversion technologies. Prussian blue analogues (PBAs) serve as promising pre-catalysts for the OER. However, PBAs, typically prepared through the conventional co-precipitation method, exhibit a lower active site density and limited electrical transport, making them suitable precursors for the derivation of PBA derivatives. In this research, we identified a significant enhancement in the electrocatalytic performance of Co-Fe Prussian blue analogue (CoFe PBA) through electrochemical oxidation. The cubic CoFe PBA was synthesized by one-step co-precipitation method using adjusting the amount of sodium citrate and potassium ferricyanide. After the electrochemical treatment, CoFe PBA demonstrates remarkable attributes, including a low overpotential of 331mV at a current density of 10mA·cm-2, a small Tafel slope of 50.4mV·dec-1, and excellent long-term stability during electrolysis in a 1M KOH alkaline medium for over 37h. Moreover, the electrochemical oxidation of CoFe PBA was comprehensive, employing techniques such as Transmission electron microscope, Powder X-ray diffraction, and X-ray photoelectron spectroscopy. These analyses confirmed the presence of real active substances, including CoOOH and a part of FeOOH species, further supporting the observed improvements in electrocatalytic activity.

Prussian blue analogue-derived ZnOCo@nitrogen-depleted g-C3N4(ND-CN) for lightweight and efficient electromagnetic wave absorption

The sustainable electromagnetic (EM) environment urgently needs the development of high-performance absorbers. This study involved synthesizing a series of ZnOCo@ND-CN (X) composites through in-situ depositing Prussian blue analogue (Zn3[Co(CN)6]2) on varying amounts of Nitrogen-Depleted g-C3N4 (ND-CN), followed by carbonization. Adjusting the amount of ND-CN in the composites can effectively regulate the dielectric constant. The as-fabricated defective structures with high electrical conductivity and the synergy between ND-CN with ZnOCo particles, as well as the presence of a variety of heterogeneous interfaces, which endow the composites with the impressive EM wave absorption properties. ZnOCo@ND-CN (0.2) simultaneously exhibits a minimum reflection loss value of −51.57 dB and a widest effective absorption bandwidth of 5.70 GHz at the thickness of only 1.7 mm with merely 8 wt% filler. This work provides a scalable strategy for the construction of multicomponent PBA-derived composites for lightweight and high-performance microwave absorption.

FeNi Prussian blue analogues on highly graphitized carbon nanosheets as efficient glucose sensors

FeNi Prussian blue analogues on highly graphitized carbon nanosheets as efficient glucose sensors

Scale-Up Preparation of Manganese-Iron Prussian Blue Nanozymes as Potent Oral Nanomedicines for Acute Ulcerative Colitis.

Prussian blue (PB) nanozymes are demonstrated as effective therapeutics for ulcerative colitis (UC), yet an unmet practical challenge remains in the scalable production of these nanozymes and uncertainty over their efficacy. With a novel approach, a series of porous manganese-iron PB (MnPB) colloids, which are shown to be efficient scavengers for reactive oxygen species (ROS) including hydroxyl radical, superoxide anion, and hydrogen peroxide, are prepared. In vitro cellular experiments confirm the capability of the nanozyme to protect cells from ROS attack. In vivo, the administration of MnPB nanozyme through gavage at a dosage of 10mgkg-1 per day for three doses in total potently ameliorates the pathological symptoms of acute UC in a murine model, resulting in mitigated inflammatory responses and improved viability rate. Significantly, the nanozyme produced at a large scale can be achieved at an unprecedented yield weighting ≈11g per batch of reaction, demonstrating comparable anti-ROS activities and treatment efficacy to its small-scale counterpart. This work represents the first demonstration of the scale-up preparation of PB analog nanozymes for UC without compromising treatment efficacy, laying the foundation for further testing of these nanozymes on larger animals and promising clinical translation.

Core-Shell MnFe Nanocatalyst Derived from Prussian Blue Analogs for Peroxymonosulfate Activation: Nonradical Mechanism and Bimetallic Valence Cycle.

Sulfamethazine (SAT) is widely present in sediment, soil, rivers, and groundwater. Unfortunately, traditional water treatment technologies are inefficient at eliminating SAT from contaminated water. Therefore, developing an effective and ecologically friendly treatment procedure to effectively remove SAT is critical. This has raised concerns about its potential impact on the environment and human health. In this study, metal-organic-inorganic composites consisting of graphene-encapsulated Fe-Mn metal catalyst (Mn3Fe1-NC) were synthesized by calcining MnFe Prussian blue analogs (PBA) under a nitrogen atmosphere. The composites were applied to activate peroxymonosulfate (PMS) and facilitate the degradation of SAT in aquatic environments. The Mn3Fe1-NC, dosed with 5 mg, in combination with PMS, dosed with 1.5 mmol L-1, achieved a 91.8% degradation efficiency of SAT. The transformation of the CN skeleton led to the formation of a carbon shell structure, which consequently reduced metal ion leaching from the material. At various pH levels, the iron and manganese ions were observed to leach out at levels lower than 0.1392 and 0.0580 mg L-1, respectively. In contrast, the Mn3Fe1-NC was found to be minimally impacted by pH levels and coexisting ions present in the aqueous environment. Radical burst experiments and electrochemical analysis tests verified that degradation primarily occurs through the nonradical pathway of electron transfer. The active sites responsible for this process were identified as the Mn (IV) and graphitic-N atoms on the material, which facilitate direct electron transfer. Additionally, the presence of Fe atoms promotes the valence cycling of Mn atoms. This study introduces new insights into the reaction mechanism and the constitutive relationship of catalytic centers in nonradical oxidation reactions.

Highly catalytic Prussian blue analogues and their application on the three-dimensional origami paper-based sweat sensors

Prussian blue analogues (PBAs) are promising materials due to their rich active sites and straightforward synthesis. However, their limited conductivity and electron transfer inefficiency hinder practical applications. This study utilizes a simple one-pot synthesis approach to produce a tungsten-disulfide (WS2) and iron-cobalt Prussian blue analogue composite (WS2-PBA), enhancing conductivity and electron transfer rate performance. Through the inclusion of sodium citrate into the solution, the S-edge site concentration of WS2 increases. This augmentation introduces additional active sites and defects into the catalyst, enhancing its catalytic activity. The effectiveness of the WS2-PBA 3D-Origami paper device for lactate detection in sweat is also evaluated for biomedical applications. The device demonstrated a robust relationship between the lactate concentration and current intensity (R2 = 0.997), with a detection limit of 1.83 mM. Additionally, this platform has successfully detected lactate in clinical sweat, correlating with the high-performance liquid chromatography test results, suggesting promising prospects for clinical diagnosis. In the future, the excellent catalytic and Rct performance of the WS2-PBA will enable its use in biomedical applications.

Optimizing Mn in Prussian blue analogs with double redox active sites to induce boosted Zn2+ storage

Prussian Blue analogs (PBAs) are a suitable aqueous zinc-ion batteries (AZIBs) cathode material, but they face issues related to low specific capacity and cycling lifespan due to insufficient active sites and poor ion de-intercalation structural stability. In this study, Mn-Prussian Blue Analog (Mn-PBA) is fabricated using a simple co-precipitation method and the morphology of Mn-PBA is further optimized through artificially manipulating concentration gradients strategy, effectively enhancing the structural stability of Zn2+ de-intercalation. Furthermore, the introduction of Mn established dual Zn2+ active centers in Mn-PBA (Mn-O and Fe(CN)6]4−/[Fe(CN)6]3−), leading to an increased specific capacity. As a proof of concept for AZIBs, the optimized Mn-PBA-3 cathode exhibits a high reversible specific capacity of 143.5 mAh/g and maintains a capacity retention of 88.5 % after 250 cycles at 1 A/g, surpassing commercial MnO2 (30.5 mAh/g after 100 cycles). Mn-PBA-3 also delivers a high capacity of 79.0 mA h g−1 after 2000 cycles of 10 A/g. The mechanism of the Zn2+ double redox reaction of Mn-PBA-3 has been revealed in detail by in situ Raman and a series of ex situ techniques. Under a high operating voltage window of 0–1.9 V, Zn//Mn-PBA-3 demonstrates a capacity of 99.3 mAh/g after 800 cycles (5 A/g) by assembling zinc ion button battery. This work has reference significance for structurally modulated PBAs used in high performance AZIBs.

Degradation of atrazine by N-doped graphitic carbon encapsulated Nickel-iron alloy via heterogeneous activation of peroxymonosulfate

Heterogeneous magnetic catalysts for peroxymonosulfate (PMS) activation that are used to degrade pollutants have attracted growing attention, and bimetallic alloy catalysts have excellent catalytic performance. In this study, nitrogen-doped graphite carbon encapsulated NiFe (NiFe@NC) alloy catalysts were synthesized using nickel-iron Prussian blue analog precursors to remove atrazine (ATZ) via the activation of PMS. The effects of various operating parameters (NiFe@NC dosage, PMS concentration, initial solution pH, and reaction temperature), and the effects of co-existing components were investigated. The synergistic catalysis of Ni and Fe gives NiFe@NC good catalytic properties. The NiFe@NC/PMS system achieved 100% removal of 10 mg L−1 ATZ was achieved in 30 min with an initial pH of 5.9; the TOF was 4.33 min−1, and the system exhibited resistance to interference from many co-existing substances. The graphite-carbon core-shell structure of NiFe@NC slowed down the leaching rate of metal ions and had good stability. Redox cycles in the system were achieved by facilitating the interaction between the transition metal and HSO5-, ensuring the continuous generation of reactive oxygen species. Ecotoxicity assessment showed that the toxicity level was significantly reduced after treatment. The total treatment cost of treating 1 m3 wastewater was lower than that of Fenton sludge catalyst. A continuous flow reactor was constructed to achieve continuous degradation of ATZ for long periods. This study expanded the application of PMS advanced oxidation technology by synthesizing an economical and recyclable magnetic catalyst and provided new insights for the removal of refractory organic matter.

Regulating valence states of CuFe-PBA for the simultaneous electrochemical detection of Cd2+, Pb2+ and Hg2+ in food application

Prussian blue analogues, as prospective electrode materials, play a crucial role in detecting heavy metal ions (HMIs), a process closely related to their electron transfer capacities and active surfaces. Here, etched copper-iron Prussian blue analogues (CuFe-PBA) are synthesized through a combination of flash nanoprecipitation (FNP) and an alkali etching process. Furthermore, this study investigates the impact of ammonia on the electronic structure of CuFe-PBA and its electrochemical detection capabilities for HMIs. The etched CuFe-PBA (e-CuFe-PBA) exhibits excellent detection performance for Cd2+, Pb2+ and Hg2+ with 17.6 μA μM−1, 24.2 μA μM−1 and 26.2 μA μM−1, respectively, due to the fact that the ammonia etching not only modulates the electronic properties of the surface of CuFe-PBA but also reduces the degree of agglomeration and enhances the accessible surface area. Additionally, it demonstrates excellent stability and resistance to interference, having been successfully applied to detect HMIs in food samples such as preserved eggs and apple juice. These results provide a new strategy for the use of Prussian blue analogues as electrochemical sensors for food safety applications.

WITHDRAWN: Progress in the advancement of medium- and high-entropy catalysts for high performance lithium-sulfur batteries

Lithium-sulfur batteries have attracted significant attention as a potential new energy storage system, thanks to their high theoretical energy density, cost-effectiveness, and environmentally friendly nature. However, the practical implementation of lithium-sulfur batteries faces inherent challenges, such as rapid capacity decay and poor cycling stability due to the dissolution of lithium polysulfides during cycling. Recent advances have made considerable progress in addressing these challenges by incorporating catalysts to facilitate redox reactions and control the shuttle effect. A notable trend in this regard is the emergence of medium- and high-entropy materials as an innovative approach to designing advanced catalysts, positioning them as promising candidates for multimetallic-based catalysts in lithium-sulfur batteries. This review examines the progress and application of medium- and high-entropy materials, including alloys, oxides, sulfides, phosphides, and prussian blue analogues, as catalysts for lithium-sulfur batteries. It explores the effects of various factors and their synergistic impacts on electrochemical performance, along with discussions on strategies of optimizing catalyst design for the improved sulfur utilization and cycling stability. Additionally, the review discusses the challenges, potential future directions, and prospects for designing medium- and high-entropy materials-based catalysts, envisioning the development of high-performance lithium-sulfur batteries for future energy storage applications.

Magnetically Controlled Photothermal, Colorimetric, and Fluorescence Trimode Assay for Gastric Cancer Exosomes Based on Acid-Induced Decomposition of CP/Mn-PBA DSNBs.

The accurate quantification of cancer-derived exosomes, which are emerging as promising noninvasive biomarkers for liquid biopsies in the early diagnosis of cancer, is becoming increasingly imperative. In our work, we developed a magnetically controlled photothermal, colorimetric, and fluorescence trimode aptasensor for human gastric cancer cell (SGC-7901)-derived exosomes. This sensor relied on CP/Mn-PBA DSNBs nanocomposites, created by decorating copper peroxide (CP) nanodots on polyethyleneimine-modified manganese-containing Prussian blue analogues double-shelled nanoboxes (PEI-Mn-PBA DSNBs). Through self-assembly, we attached CD63 aptamer-labeled CP/Mn-PBA DSNBs (Apt-CP/Mn-PBA DSNBs) to complementary DNA-labeled magnetic beads (cDNA-MB). During exosome incubation, these aptamers preferentially formed complexes with exosomes, and we efficiently removed the released CP/Mn-PBA DSNBs by using magnetic separation. The CP/Mn-PBA DSNBs exhibited high photoreactivity and photothermal conversion efficiency under near-infrared (NIR) light, leading to temperature variations under 808 nm irradiation, correlating with different exosome concentrations. Additionally, colorimetric detection was achieved by monitoring the color change in a 3,3',5,5'-tetramethylbenzidine (TMB) system, facilitated by PEI modification, NIR-enhanced peroxidase-like activity of CP/Mn-PBA DSNBs and their capacity to generate Cu2+ and H2O2 under acidic conditions. Moreover, in the presence of Cu2+ and ascorbic acid (AA), DNA sequences could form dsDNA-templated copper nanoparticles (CuNPs), which emitted strong fluorescence at around 575 nm. Increasing exosome concentrations correlated with decreases in temperature, absorbance, and fluorescence intensity. This trimode biosensor demonstrated satisfactory ability in differentiating gastric cancer patients from healthy individuals using human serum samples.

CoS2/Ni3S4 − N − C heterostructured electrode materials derived from Prussian-blue analogs for supercapacitors

Prussian blue analogues (PBAs) have the advantages of dependable electrochemical performance and long service life when used as energy storage materials because of their face-centered cubic structure. In this case, the appropriate metal sulfide derivatives were created using NiCo prussian blue analogue nano units as a precursor, which took on the precursor's structural traits. More reaction sites are exposed by this distinctive structural design, and a little quantity of nitrogen-doped carbon is produced, which improves charge transfer. The box-like structure has a buffer effect on the stress of the active material during charging and discharging, and the heterostructure of mixed metal sulfides and nitrogen-doped carbon composite cubic can both significantly increase the electrode's electrochemical capacitance and cycling stability. The CoS2/Ni3S4–N–C offers a capacitance of 817C g−1 at 3 A g−1 and 556C g−1 at 20 A g−1. The CoS2/Ni3S4–N–C electrode also has outstanding cycle stability (98.2 % capacitance retention after 10,000 cycles). An asymmetric supercapacitor (ASC) device made of CoS2/Ni3S4–N–C with activated carbon electrodes exhibits exceptional cycle stability. With a retention rate of 103.7 % after 10,000 cycles at 10 A g−1 and an energy density of 40 Wh kg−1. Using density functional theory (DFT), the electron characteristics of Co2NiO4 and CoS2/Ni3S4–N–C are compared. CoS2/Ni3S4–N–C detected more state densities at the Fermi level, which causes more charge to accumulate. This shows that the heterojunction's electron conductivity is significantly greater than the oxide's, and ultimately leads to quicker reaction kinetics.