Platinum Nanoparticles Research Articles

One-step electrochemical preparation of platinum nanoparticle decorated self-healing reduced graphene oxide three-dimensional nanoarray for portable detection of bisphenol A

Highly selective and sensitive analysis of bisphenol A (BPA) in many plastic products remains its significance. We explored a simple, highly sensitive, and inexpensive electrochemical sensor based on a self-healing three-dimensional nanoarray (3DN) via a single-step electrochemical preparation of both platinum nanoparticles (PtNPs) and reduced graphene oxide (rGO) on a glassy carbon electrode for the portable detection of bisphenol (BPA) in plastic bottled waters. The structure of PtNPs/3DNrGO was confirmed by electron microscope and spectroscopic characterization. Electrochemical characteristics indicated that PtNPs/3DNrGO could decrease the oxidation overpotential due to the self-healing effect of the physical interaction between PtNPs and hydroxyl groups of rGO with an increase in the active surface area. The PtNPs/3DNrGO exhibited remarkably efficient electrocatalytic performance for the oxidation of BPA. The PtNPs/3DNrGO sensor for BPA demonstrated a wide linear range from 0.7 to 20 µM with a low limit of detection of 6 nM (S/N = 3) and effective performance including high sensitivity, high repeatability, and excellent selectivity. The developed sensor had been effectively implemented to assess BPA in plastic samples with desirable impacts. The interaction mechanism of both PtNPs and rGO was inferred by density functional theory. The proposed electrochemical sensor enabled the development of a portable, low-cost, and user-friendly monitoring of water quality, which will offer theoretical support for environmental monitoring.

Ag-Pt@BSA bimetallic nanoparticles for breast cancer radiation treatment dose augmentation

Cancer has traditionally been treated with surgery and chemotherapy. Radiation therapy (RT) is a branch of oncology based on radiation therapy that can be used alone or in combination with surgery and chemotherapy to achieve local control of breast cancer. Radiosensitizers make tumor cells more responsive and sensitive to ionizing radiation, consequently facilitating production of free radicals and hastening DNA damages. Stages I to III of breast cancer is managed with curative intent with multimodality treatment including radiotherapy. The current cancer therapies in particular radiotherapy have a high risk of serious side effects to the healthy tissues and do not guarantee remission. In response to this challenge, the present study developed bovine serum albumin capped platinum and silver nanoparticles (Ag-Pt@BSA NPs), a bimetallic radiosensitizer, which is a remedy to the aforementioned issue. This research makes use of a nanoplatform that contains two high-Z nanoparticles— Pt and Ag. A variety of methods were used to fully characterize the developed Ag-Pt@BSA NPs. Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), UV–Vis, X-ray diffractometery (XRD) and energy-dispersive X-ray spectroscopy (EDS) techniques were used to investigate the physical and chemical features of designed bimetallic nanoradiosensitizer. The Ag-Pt@BSA naoradiosensitizer was proven to have successfully prepared by FTIR, XRD and EDX. According to the DLS result, the hydrodynamic size of the NPs is 35.42 nm, and the average diameter in the TEM image is around 7.8 ± 2.6 nm. The initial hydrodynamic size Ag-Pt@BSA was around 35 nm and within the storage time its size remained below 40 nm which indicating the unique colloidal stability of fabricated nanoradiosensitizers. The zeta potential of Ag-Pt@BSA radio-enhancement was determined to be approximately −17.9 mV, providing additional support for the nanoparticles’ colloidal stability. The results showed that the utilization of Ag-Pt@BSA NPs in conjunction with X-ray irradiation could substantially enhance the effectiveness of cancer therapy. This is supported by research, examining a series of in vitro tests including reactive oxygen species generation (ROS), cell viability, apoptosis and colony formation assay. Furthermore, the dosage-dependent radiosensitizing ability of the Ag-Pt@BSA NPs was also observed in the apoptosis and MTT assay against 4 T1 cells by increasing the localized radiation dosage. Ag-Pt@BSA NPs could be a potential radio-enhancer agent against breast cancers and, by extension, other cancers, since it multiplies the therapeutic effect of low-dose radiation while reducing the damage to normal tissues compared to high-dose radiation therapy. Increasing the concentration of Ag-Pt@BSA NPs and the dosage of X-ray irradiation boosted the radiosensitizing capacity in a dose-dependent way.

Microchanneling and ultrasonic delivery of gold and platinum nanoparticles for selective photothermolysis of sebaceous follicles in the treatment of acne: a pilot study using porcine skin.

Several treatment options for acne vulgaris are limited by their associated adverse effects. An innovative approach involves introducing light-absorbing nanoparticles into sebaceous follicles before destroying the follicles using selective photothermolysis. We aimed to investigate efficient methods for introducing gold and platinum nanoparticles into sebaceous follicles and to identify suitable laser equipment and parameters for the effective destruction of these follicles. We used porcine skin as the experimental model. We compared the efficacies of a thulium laser, ultrasound, and manual massage and evaluated the optimal method for delivering nanoparticles in close proximity to sebaceous follicles. Subsequently, a 1064-nm-wavelength neodymium-doped yttrium aluminum garnet (Nd: YAG) laser was employed to induce selective photothermolysis. We compared different parameters to identify the optimal pulse duration and fluence of the Nd: YAG laser. The extent of penetration and destruction of sebaceous follicles was assessed using hematoxylin and eosin (H&E) staining, and a numerical evaluation was conducted. H&E staining showed that irradiation with a long-pulsed Nd: YAG laser following a combination of thulium laser and sonophoresis effectively destroyed sebaceous follicles, with destruction rates exceeding 50%. These results were valid with a long pulse duration and a high fluence of the Nd: YAG laser. This study demonstrated that sebaceous follicles can be effectively destroyed through a mixture of gold and platinum nanoparticle delivery by a combination of microchanneling and sonophoresis, followed by selective thermal damage induced by a 1064-nm long-pulsed high-fluence Nd: YAG laser.

Application of Platinum Nanoparticles Decorating Mesoporous Carbon Derived from Sustainable Source for Hydrogen Evolution Reaction

The perpetually fluctuating economic and environmental climate significantly increases the demand for alternative fuel sources. The utilization of hydrogen gas is a viable option for such a fuel source. Hydrogen is one of the most energy-dense known substances; however, it is unfortunately also highly volatile, especially in the diatomic gaseous state most commonly used to store it. The utilization of a hydrogen feedstock material such as sodium borohydride (NaBH4) may prove to mitigate this danger. When NaBH4 reacts with water, hydrogen stored within its chemical structure is released. However, the rate of hydrogen release is slow and thus necessitates a catalyst. Platinum nanoparticles were chosen to act as a catalyst for the reaction, and to prevent them from conglomerating, they were embedded in a backbone of mesoporous carbon material (MCM) derived from a sustainable corn starch source. The nanocomposite (Pt-MCM) was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Pt-MCM underwent catalytic testing, revealing that the catalytic activity of the Pt-MCM composite catalysts increased with increasing quantities of sodium borohydride, lower pH levels, and higher temperatures. The activation energy of the catalyzed reaction was found to be 37.7 kJ mol−1. Reusability experiments showed an initial drop off in hydrogen production after the first trial but subsequent stability. This Pt-MCM catalyst’s competitive activation energy and sustainable MCM backbone derived from readily available corn starch make it a promising option for optimizing the hydrogen generation reaction of NaBH4.

Nickel ferrite decorated noble metal containing nitrogen-doped carbon nanotubes as potential magnetic separable catalyst for dinitrotoluene hydrogenation

The 2,4-toluenediamine (TDA) is one of the most important chemicals in the polyurethane industry, produced by the catalytic hydrogenation of 2,4-dinitrotoluene (DNT). The development of novel catalysts that can be easily recovered from the reaction mixture is of paramount importance. In our work, a NiFe2O4/N-BCNT supported magnetic catalyst was prepared by a modified coprecipitation method. The catalyst support alone also showed activity in the synthesis of TDA. Platinum nanoparticles were deposited on the catalyst support surface by a fast, relatively simple, and efficient sonochemical method, resulting in a readily applicable catalytically active system. The prepared catalyst exhibited high activity in hydrogenation tests, which was proved by the exceptionally high DNT conversion (100% for 120 min at 333 K) and TDA yield (99%). Furthermore, the magnetic catalyst can be easily recovered from the reaction medium by the action of an external magnetic field, which can greatly reduce catalyst loss during separation.

Tailoring Catalysis of Encapsulated Platinum Nanoparticles by Pore Wall Engineering of Covalent Organic Frameworks.

While supported metal nanoparticles (NPs) have shown significant promise in heterogeneous catalysis, precise control over their interaction with the support, which profoundly impacts their catalytic performance, remains a significant challenge. In this study, Pt NPs are incorporated into thioether-functionalized covalent organic frameworks (denoted COF-Sx), enabling precise control over the size and electronic state of Pt NPs by adjusting the thioether density dangling on the COF pore walls. Notably, the resulting Pt@COF-Sx demonstrate exceptional selectivity (> 99 %) in catalytic hydrogenation of p-chloronitrobenzene to p-chloroaniline, in sharp contrast to the poor selectivity of Pt NPs embedded in thioether-free COFs. Furthermore, the conversion over Pt@COF-Sx exhibits a volcano-type curve as the thioether density increases, due to the corresponding change of accessible Pt sites. This work provides an effective approach to regulating the catalysis of metal NPs via their microenvironment modulation, with the aid of rational design and precise tailoring of support structure.

One-step green synthesis of platinum mesoporous nanoparticles by riboflavin for light activated antitumoral therapy

Photodynamic therapy (PDT) has been established as one of the most promising novel cancer therapies with fewer side-effects and enhanced efficacy compared to the currently available conventional treatments. However, its application has been hindered by the limitations that photosensitizers (PS) have. The combination of PS with metallic nanoparticles like platinum nanoparticles (PtNPs), can help to overcome these intrinsic drawbacks. In this work, the combination of PtNPs and the natural photosensitizer riboflavin (RF) is proposed. PtNPs are synthesized using RF (Pt@RF) as reducing and stabilizing agent in a one-step method, obtaining nanoparticles with mesoporous structure for UV triggered PDT. In view of possible future UV irradiation treatments, the degradation products of RF, ribitol (RB) and lumichrome (LC), this last being a photosensitizing byproduct, are also employed for the synthesis of porous PtNPs, obtaining Pt@LC and Pt@RB. When administered in vitro to lung cancer cells, all the samples elicit a strong decrease of cell viability and a decrease of intracellular ATP levels. The antitumoral effect of both Pt@RF and Pt@LC is triggered by UV-A irradiation. This antitumoral activity is caused by the induction of oxidative stress, shown in our study by the decrease in intracellular glutathione and increased expression of antioxidant enzymes.

Electrochemical Detection of Nitrite on PANI-TiO2/Pt Nanocomposite-Modified Carbon Paste Electrodes Using TOPSIS and Taguchi Methods.

Platinum nanoparticles are widely used in electrocatalysis and sensors. In this work, a novel modified carbon paste electrode based on PANI-TiO2/Pt nanocomposites was developed electrochemically. To improve the performance of the PANI-TiO2/Pt composite-modified electrode, a Taguchi orthogonal array was used for experimental design, and the best values of factors affecting the performance were determined using the technique for order preference by similarity to ideal solution (TOPSIS) and Taguchi optimization methods. The electrochemical catalytic activities of the PANI-TiO2/Pt composite-modified electrode on the oxidation of nitrite was calculated by electrochemical analysis. The experimental results demonstrate that the PANI-TiO2/Pt electrode has pretty excellent electrocatalytic ability for the oxidation of nitrite. The sensing performances of the proposed electrode were evaluated, including linear detection range, sensitivity, LOD, selectivity, and stability for nitrite sensing.

Fusarium oxysporum mediated synthesis of nitrogen-doped carbon supported platinum nanoparticles for supercapacitor device and dielectric applications

A scalable method has been developed for synthesizing nitrogen-doped carbon-supported platinum nanoparticles. Fusarium oxysporum was utilized as reducing and stabilizing agent, and calcination was employed to produce the carbon support. The unique properties of Fusarium oxysporum facilitate the reduction of metal ions while preventing agglomeration and maintaining nanoparticle stability. An extensive investigation of the electrochemical supercapacitor and temperature-dependent dielectric properties of the nanoparticles demonstrates their suitability for supercapacitor applications. Electrochemical analysis showed N-doped C/Pt NPs with high specific capacitance, 482.77F/g at 2.0 A/g, retaining 94 % capacitance even under 20 A/g after 10,000 cycles. The symmetric supercapacitor device displayed 275F/g at 2 A/g, maintaining 61.10 Wh/kg energy density at 1000 W/kg power density, with ∼ 92 % capacitance retention after 10,000 cycles. Dielectric properties of N-doped C/Pt NPs were analyzed at both ambient (300 K) and elevated (450 K) temperatures, revealing temperature-dependent characteristics and alternating current conductivity. At 0.75 MHz, the dielectric permittivity (ɛ’) was measured at 31, with tangent loss at 2.01 and a.c. conductivity at 2.597 × 10-3 O−1 m−1. Increasing the frequency to 6.0 MHz resulted in a 2.38-fold rise in dielectric permittivity and a decrease in tangent loss to 0.77, demonstrating the temperature-sensitive nature of dielectric relaxation.

Photocatalytic Hydrosilylation over Pt@UiO-66-NH2: Enhanced Activity and Polymerization Kinetics.

Metal-organic frameworks (MOFs) have shown great research and application value in various types of hydrosilylation reactions. However, studies on photocatalysis-induced hydrosilylation using MOFs are extremely rare. Metal nanoparticles (MNPs)@MOFs are extensively studied for their excellent structural tunability and photocatalytic activity, but there are few reports on their application in photocatalytic hydrosilylation. Here, a novel photocatalyst consisting of platinum (Pt) nanoparticles immobilized in a MOF framework is synthesized and used for photocatalytic hydrosilylation. The effects of various factors on hydrosilylation conversion are investigated, including catalyst concentration, substrate ratio, and irradiation intensity. Furthermore, the photoreactivity of the synthesized Pt catalyst is evaluated in the presence of different concentrations of 2-chlorothixanthone as a photosensitizer. It is noteworthy that the conversion of the reaction increases with increasing catalyst concentration or photosensitizer concentration, whereas increasing the polymethylhydrosiloxane content does not lead to a significant increase in conversion. This study demonstrates the potential of MNPs@MOFs as efficient photocatalysts for photoinduced hydrosilylation reactions and paves the way for future applications in this area.

Au-Pt Coating Improved Catalytic Stability of Au@AuPt Nanoparticles for Pressure-Based Point-of-Care Detection of Escherichia coli O157:H7.

Point-of-care testing (POCT) technologies facilitate onsite detection of pathogens in minutes to hours. Among various POCT approaches, pressure-based sensors that utilize gas-generating reactions, particularly those catalyzed by nanozymes (e.g., platinum nanoparticles, PtNPs, or platinum-coated gold nanoparticles, and Au@PtNPs) have been shown to provide rapid and sensitive detection capabilities. The current study introduces Au-Pt alloy-coated gold nanoparticles (Au@AuPtNPs), an innovative nanozyme with enhanced catalytic activity and relatively high stability. For pathogen detection, Au@AuPtNPs are modified with H1 or H2 hairpin DNAs that can be triggered to undergo a hybridization chain reaction (HCR) that leads to their aggregation upon recognition by an initiator strand (Ini) with H1-/H2-complementary aptamers tethered to magnetic beads (MBs). Pathogen binding to the aptamer exposes Ini, which then binds Au@AuPtNPs and initiates a HCR, resulting in Au@AuPtNP aggregation on MBs. These Au@AuPtNP aggregates exhibit strong catalysis of O2 from the H2O2 substrate, which is measured by a pressure meter, enabling detection of Escherichia coli (E. coli) O157:H7 at concentrations as low as 3 CFU/mL with high specificity. Additionally, E. coli O157:H7 could also be detected in simulated water and tea samples. This method eliminates the need for costly, labor- and training-intensive instruments, supporting its further testing and validation for deployment as a rapid-response POCT application in the detection of bacterial contaminants.

Biosynthesis of Platinum Nanoparticles PlNPs by Bacterial Strain Rhodococcus erythropolis

The biosynthesis of platinum nanoparticles (PlNPs) using the bacterial strain Rhodococcus erythropolis offers a greener alternative to conventional chemical and physical synthesis methods. This study explores the potential of R. erythropolis to produce PlNPs by leveraging its biological machinery to reduce platinum ions and stabilize the resulting nanoparticles. The biosynthesis was conducted under varying conditions of pH, temperature, and sodium platinite concentrations to optimize yield and particle characteristics. The nanoparticles were characterized. The outcome reflects that PlNPs exhibit distinct size-dependent optical properties and crystallinity, with extracellular proteins from R. erythropolis playing a crucial role in nanoparticle stabilization. The optimized biosynthesis process produced PlNPs with high colloidal stability and significant potential for applications in catalysis and environmental remediation. This study advances the understanding of microbial nanoparticle production, highlighting a sustainable pathway for the synthesis of biocompatible and catalytically active platinum nanoparticles.

Synergetic Effect between Platinum Nanoparticles and Single Atoms Revealed in the Catalytic Mechanism of Traditional Pt/C for the Oxygen Reduction Reaction

Synergetic Effect between Platinum Nanoparticles and Single Atoms Revealed in the Catalytic Mechanism of Traditional Pt/C for the Oxygen Reduction Reaction

Boron carbon nitride as efficient oxygen reduction reaction support

The electrocatalytic oxygen reduction reaction (ORR) is crucial for energy conversion systems such as fuel cells and metal-air batteries. Boron carbon nitrogen (BCN) is a novel functional material with a high specific surface area, excellent corrosion resistance, and outstanding electrochemical stability. These properties make BCN an effective ORR catalyst and a promising support for metal catalysts. This study leveraged the strong interaction between BCN and metals to anchor platinum nanoparticles (Pt NPs) onto the BCN surface (Pt/BCN), significantly enhancing the durability of traditional Pt/C catalysts in ORR. The half-wave potential of Pt/BCN is 0.927 V, higher than Pt/XC-72R (0.857 V) and commercial Pt/C (0.879 V). Notably, after 10,000 durability test cycles, the mass activity (MA) of Pt/XC-72R and commercial Pt/C decreased by 67 % and 75 %, respectively. Even after 50,000 cycles, Pt/BCN exhibited only a 54 % decrease in MA. Experimental data and density functional theory calculations confirmed increased electron transfer from Pt to the BCN support, indicating a strong electronic metal-support interaction (EMSI) between Pt and BCN. This strong EMSI effectively anchored the Pt NPs, preventing migration and aggregation during the ORR process. Consequently, our research introduces a novel electrocatalyst support material with significant potential for ORR and broader applications.

Point-of-care testing of Pseudomonas aeruginosa using PCN-222(Pt) prepared by nanoconfinement-guided protocol to catalyze gas generation reaction

BackgroundPathogenic bacteria are keeping threatening global public health since they can cause many infectious diseases. The traditional microorganism identification and molecular diagnostic techniques are insufficiently sensitive, time-consuming, or expensive. Thus it is of great interest to establish pressure signal-based sensing platforms for point-of-care testing of pathogenic bacteria to achieve timely diagnosis of infectious diseases. Rational design and synthesis of nano-sized probes with high peroxidase-mimicking activity have been a long-term cherished goal for improving the sensitivity of pressure signal-based sensing methods. ResultsGuided by nanoconfinement effect, PCN-222(Pt) was prepared by confining Pt clusters within the channels of a zirconium porphyrin MOFs material termed as PCN-222. In comparison to regular platinum nanoparticles, palladium@platinum core-shell nanodendrites, and platinum-coated gold nanoparticles, the prepared PCN-222(Pt) displayed superior peroxidase-mimicking activity with outstanding efficiency for catalyzing the decay of H2O2 to produce O2. Thus it was used as a pressure signal probe to establish a sensitive method on a hydrogel pellets platform for analyzing Pseudomonas aeruginosa (P. aeruginosa), for which polymyxin B and a phage termed as JZ1 were used as recognition agents for the target pathogen. P. aeruginosa was quantified with a handheld pressure meter within a broad range of 2.2 × 102–2.2 × 107 cfu mL−1. This method was used to quantify P. aeruginosa in various biological and food samples with acceptable accuracy and reliability. SignificanceThe proposed nanoconfinement-guided protocol provides a novel approach for rational design and preparation of nano-sized probes with high peroxidase-mimicking activity for catalyzing gas-generation reaction. Thus this study opens an avenue for establishment of sensitive pressure signal-based sensing methods for pathogenic bacteria, which shows broad application prospects in medical diagnosis of infectious diseases.

Naproxen electrooxidation using carbon paper electrodes modified with reduced graphene oxide and platinum nanoparticles

This research study investigates the electrooxidation of naproxen (NPX), an anti-inflammatory pharmaceutical, on modified carbon paper (CP) electrodes. Electrochemical modification of CP electrodes was accomplished with Pt or reduced graphene oxide (RGO)-Pt coatings, resulting in the production of electroactive electrodes. RGO coatings synthesized by cyclic voltammetry (CV) for 10 scans provided the optimal coverage for the CP electrode surface. The deposition of Pt nanoparticles (Pt NPs) on the electrodes (CP or CP-RGO) by CV produced a good electrode surface coverage with 20 synthesis scans. The voltammetric analysis of the electrodes in 230 mg/L NPX solution showed oxidation peaks around 1.0 to 1.2 V. Moreover, the inclusion of RGO in the coating led to an increase in the current density of these oxidation peaks and a decrease of the electrode electron transfer resistance as measured by electrochemical impedance spectroscopy.The electrolysis of NPX in different electrolytes (Na2SO4 and Na2SO4/NaCl) was conducted at 1.4 V, and the removal of NPX was analyzed using high-performance liquid chromatography. The CP-RGO-Pt electrode in Na2SO4/NaCl media showed the fastest NPX degradation kinetics, resulting in a 90 % degradation in only 90 min with low charge consumption (0.07 A·h·L-1). The smaller size of Pt NPs deposited on CP-RGO, as observed by field emission scanning electron microscopy and transmission electron microscopy, contributed to the higher electrochemical response in CV and a faster kinetic degradation of NPX.

Magnetically Guided Theranostics: Novel Nanotubular Magnetic Resonance Imaging Contrast System Using Halloysite Nanotubes Embedded with Iron–Platinum Nanoparticles for Hepatocellular Carcinoma Treatment

Halloysite nanotubes (HNTs) have a layered structure of clay silicate minerals and a tubular shape, which is suitable for the uniform loading of small substrates and drug molecules. The inner diameter of HNTs with an acidic solvent is selectively etched to increase the loading capacity of magnetic iron–platinum (FePt) nanoparticles. The FePt nanoparticles and etched HNTs (eHNT) are then composited by vacuum decompression. The resulting product is named FePt@eHNT and is used as a contrast agent for T2‐weighted magnetic resonance imaging. According to a comprehensive analysis of the material and its magnetic properties, by adding different proportions of HNTs before and after modification, the saturation magnetization can reach 23.769 emu g−1, which is higher than that of the composite materials studied in previous studies. This is because the tubular structure promotes the orderly displacement of the FePt nanoparticles under three‐dimensional space constraints and the uniform effect of the magnetic field. In addition, the magnetothermal effect of the composite material is observed and its potential as an imaging agent is investigated. In this study, the enhancement of its ferromagnetism and its potential to become a multifunctional composite material for applications in drug delivery, magnetic hyperthermia, and bioimaging is demonstrated.

Optical Fiber-Enabled In Situ Photocatalytic Hydrogen Generation for Infiltrating Tumor Therapy in Brain.

In addition to repressing proliferation, inhibiting infiltration of tumor cells is an important strategy to improve the treatments of malignant tumors. Herein, a photocatalyst (pCNMC@Pt) is designed by sequentially assembling manganese dioxide, chlorin e6, and platinum (Pt) nanoparticles onto protonated graphitic carbon nitride. With the help of Z-scheme structure and near-infrared (NIR) photosensitizer, pCNMC@Pt is capable of responding to NIR light to generate large amounts of hydrogen (H2). Taking lactic acid in tumor microenvironment as sacrificial reagent, H2 therapy initiated by the NIR photocatalyst remarkably impedes the growth of glioblastoma (GBM). More importantly, it is found that H2 can suppress the stemness of gliomas stem cells, curbing both proliferation and infiltration of GBM. Furthermore, since pCNMC@Pt and light source is precisely co-localized through a self-built loading and illumination system, GBM in mouse brains can be efficiently treated, providing an alternative gas therapy approach to cure infiltrating tumors. This article is protected by copyright. All rights reserved.

Non-Invasive Detection of Early-Stage Fatty Liver Disease via an On-Skin Impedance Sensor and Attention-Based Deep Learning.

Early-stage nonalcoholic fatty liver disease (NAFLD) is a silent condition, with most cases going undiagnosed, potentially progressing to liver cirrhosis and cancer. A non-invasive and cost-effective detection method for early-stage NAFLD detection is a public health priority but challenging. In this study, an adhesive, soft on-skin sensor with low electrode-skin contact impedance for early-stage NAFLD detection is fabricated. A method is developed to synthesize platinum nanoparticles and reduced graphene quantum dots onto the on-skin sensor to reduce electrode-skin contact impedance by increasing double-layer capacitance, thereby enhancing detection accuracy. Furthermore, an attention-based deep learning algorithm is introduced to differentiate impedance signals associated with early-stage NAFLD in high-fat-diet-fed low-density lipoprotein receptor knockout (Ldlr-/-) mice compared to healthy controls. The integration of an adhesive, soft on-skin sensor with low electrode-skin contact impedance and the attention-based deep learning algorithm significantly enhances the detection accuracy for early-stage NAFLD, achieving a rate above 97.5% with an area under the receiver operating characteristic curve (AUC) of 1.0. The findings present a non-invasive approach for early-stage NAFLD detection and display a strategy for improved early detection through on-skin electronics and deep learning.

Zinc-Based ROS Amplifiers Trigger Cancer Chemodynamic/Ion Interference Therapy Through Self-Cascade Catalysis.

Nanozyme-mediated chemodynamic therapy has emerged as a promising strategy due to its tumor specificity and controlled catalytic activity. However, the poor efficacy caused by low hydrogen peroxide (H2O2) levels in the tumor microenvironment (TME) poses challenges. Herein, an H2O2 self-supplying nanozyme is constructed through loading peroxide-like active platinum nanoparticles (Pt NPs) on zinc peroxide (ZnO2) (denoted as ZnO2@Pt). ZnO2 releases H2O2 in response to the acidic TME. Pt NPs catalyze the hydroxyl radical generation from H2O2 while reducing the mitigation of oxidative stress by glutathione, serving as a reactive oxygen (ROS) amplifier through self-cascade catalysis. In addition, Zn2+ released from ZnO2 interferes with tumor cell energy supply and metabolism, enabling ion interference therapy to synergize with chemodynamic therapy. In vitro studies demonstrate that ZnO2@Pt induces cellular oxidative stress injury through enhanced ROS generation and Zn2+ release, downregulating ATP and NAD+ levels. In vivo assessment of anticancer effects showed that ZnO2@Pt could generate ROS at tumor sites to induce apoptosis and downregulate energy supply pathways associated with glycolysis, resulting in an 89.7% reduction in tumor cell growth. This study presents a TME-responsive nanozyme capable of H2O2 self-supply and ion interference therapy, providing a paradigm for tumor-specific nanozyme design.