Polypyrrole Nanoparticles Research Articles

Genosensor based on polypyrrole and dendrimer-coated gold nanoparticles for human papillomavirus detection

Human Papillomavirus (HPV) is an often asymptomatic widespread sexually transmitted infection responsible for causing various health issues. Low-risk HPV primarily causes genital warts. High-risk HPV types are associated with several cancers, including cervical, anal, and oropharyngeal cancers, posing significant health risks. In this work, we developed an electrochemical biosensor for the detection and differentiation of HPV genotypes based on electropolymerized polypyrrole (PPy) and PAMAM dendrimer-coated gold nanoparticles (PAMAM-AuNPs) for the immobilization of a DNA probe for detecting different HPV genotypes. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and atomic force microscopy (AFM) were used to characterize the biosensor. AFM analysis revealed varied topographic surfaces associated with the increased peaks concerning the biosensor and against patient samples. Electrochemical responses indicated that the genosensor could detect HPV using plasmid (HPV 6, 16, 18, 31, and 33) and cDNA samples (HPV 6, 18, and 31) from infected patients. Different electrochemical profiles were obtained between high-risk and low-risk genotypes. The sensor presented an excellent analytical performance, presenting a lower LOD of 0.04 pg.µL−1 and 0.34 pg.µL−1 for plasmidial and cDNA samples, respectively. Electrochemical analysis pointed out the ability of the developed genosensor platform to differentiate the HPV genotypes. The proposed biosensor is a promising tool for detecting and monitoring HPV and related diseases such as cervical cancer.

Alleviating rheumatoid arthritis with a photo-pharmacotherapeutic glycan-integrated nanogel complex for advanced percutaneous delivery

The prospective of percutaneous drug delivery (PDD) mechanisms to address the limitations of oral and injectable treatment for rheumatoid arthritis (RA) is increasing. These limitations encompass inadequate compliance among patients and acute gastrointestinal side effects. However, the skin’s intrinsic layer can frequently hinder the percutaneous dispersion of RA medications, thus mitigating the efficiency of drug delivery. To circumvent this constraint, we developed a strontium ranelate (SrR)-loaded alginate (ALG) phototherapeutic hydrogel to assess its effectiveness in combating RA. Our studies revealed that this SrR-loaded ALG hydrogel incorporating photoelectrically responsive molybdenum disulfide nanoflowers (MoS2 NFs) and photothermally responsive polypyrrole nanoparticles (Ppy NPs) to form ALG@SrR-MoS2 NFs-Ppy NPs demonstrated substantial mechanical strength, potentially enabling delivery of hydrophilic therapeutic agents into the skin and significantly impeding the progression of RA. Comprehensive biochemical, histological, behavioral, and radiographic analyses in an animal model of zymosan-induced RA demonstrated that the application of these phototherapeutic ALG@SrR-MoS2 NFs-Ppy NPs effectively reduced inflammation, increased the presence of heat shock proteins, regulatory cluster of differentiation M2 macrophages, and alleviated joint degeneration associated with RA. As demonstrated by our findings, treating RA and possibly other autoimmune disorders with this phototherapeutic hydrogel system offers a distinctive, highly compliant, and therapeutically efficient method.

Thin film synthesis and photovoltaic performance of polypyrrole@cobalt hydroxide composites for solar cells and optoelectronic devices

Mono-nanocomposites (MNCs) comprising polypyrrole (PPy) and cobalt hydroxide nanoparticles (Co(OH)2 NPs) are emerging as highly favorable contenders for applications in solar cells and optoelectronic devices, owing to their distinctive attributes encompassing robust light absorption, elevated conductivity, and commendable chemical stability. This investigation delves into the production of a thin film [PPy@Co(OH)2]MNC utilizing the physical vapor deposition (PVD) method. The structural and morphological characteristics of the [PPy@Co(OH)2]MNC thin film were scrutinized through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties, namely reflectance (R), absorbance (Abs), and transmittance (T) within the UV–vis–NIR spectrum, were precisely gauged at room temperature. Time-dependent density functional theory (TD-DFT) calculations and optimizations were conducted to analyze the geometric parameters, while the refractive index dispersion was probed using the single oscillator Wemple-Didomenico (WD) model. Additionally, the energy of a single oscillator and the energy of dispersion were quantified. The [PPy@Co(OH)2]MNC thin film exhibited pronounced light absorption across the UV–vis–NIR spectrum, characterized by a bandgap of 1.6 eV. The Au/[PPy@Co(OH)2]MNC/p-Si/Al heterojunction device demonstrated a power conversion efficiency and fill factor (FF) of 2.6 % and 55.07 %, respectively, under an irradiance of 100 W/cm2. The findings of this investigation underscore the potential of [PPy@Co(OH)2]MNC-based thin films as auspicious candidates for deployment in solar cells and optoelectronic devices.

Light-Driven Green-Fabricated Artificial Intelligence-Enabled Micro/Nanorobots for Multimodal Phototherapeutic Management of Bladder Cancer.

Combination therapy based on precise phototherapies combined withimmunemodulation provides successful antitumor effects. In this study, a combination therapy is designed based on phototactic, photosynthetic, and phototherapeutic Chlamydomonas Reinhardtii (CHL)-glycol chitosan (GCS)-polypyrrole (PPy) nanoparticle (NP)-enhanced immunity combined with the tumor microenvironment turnover of cytotoxic Tcells and M1/M2 macrophages, which is based on photothermal GCS-PPy NPsdecorated onto the phototactic and photosyntheticCHL. Phototherapy based on CHL-GCS-PPy NPs alleviates hypoxia and modulates the tumor immunemicroenvironment, which induces tumor cell death. In particular, the precise antitumor immune response and potent immune memory induced by combining self-navigated phototherapies significantly alleviate the progression of bladder cancer in C57BL/6 mice and effectively inhibit bladder tumor growth. Furthermore, they also potentially prevent tumor recurrence, which provides a promising therapeutic strategy for clinical tumor therapy.

Enhanced Positive Charge Performance in Triboelectric Series: Molecular Engineering of Conjugated Mesoporous Fibers for Machine Learning-Based Wearable Sensors.

With the increasing focus on triboelectric-based sensors, research on synthesizing dielectric layers from specific substances is gradually emerging. Despite numerous negatively-charged triboelectric materials, there is a scarcity of synthesizable positively-charged materials, creating a research gap. This study demonstrates the molecular design of a conjugated, mesoporous, self-assembled sheet via bottom-up synthesis. The synthesized sheet is functionalized to create a triboelectric nanogenerator. Its large specific surface area, softness, and internal space increase the actual contact area and provide adsorption sites for polypyrrole nanoparticles. The incorporation of -COO functional group enhances positive triboelectric performance, forming a dielectric layer with charge-trapping capabilities. When contact with polytetrafluoroethylene (PTFE), this structure boosts the output voltage, showing significant amplification after charge injection with minimal decay. As a demonstration, the bilayer structure is applied as a touchpad on the experimenter's arm to write symbols. The signals are input into an innovative machine-learning model to interpret the writer's intent. Additionally, the device connects to a terminal for real-time medical services, suggesting practical applications for wearable triboelectric sensors with artificial intelligence.

A chitosan-based light-curing hydrogel dressing for accelerated healing of infected wounds

Bacterial infections, excessive reactive oxygen species (ROS) accumulation and a persistent inflammatory response severely impede the wound healing process. In this study, we developed a novel multifunctional hydrogel dressing (LCPN) based on lipoic acid modified chitosan (LAMC), polypyrrole nanoparticles (PPy NPs) and nicotinamide mononucleotide (NMN) for accelerated healing of infected wounds. The synthesized LCPN hydrogel has several properties. Modification of lipoic acid significantly enhances the water solubility of chitosan making it easier to dissolve and absorb wound secretions. Interestingly, owing to the breaking and restructuring of disulfide bonds, LCPN hydrogel can be quickly bonded under UV light without relying on photoinitiators. In addition, the incorporation of PPy NPs not only enhances the electrical conductivity of LCPN hydrogel, but also confers photothermal antimicrobial capability to LCPN hydrogel. More importantly, the sustained release of NMN in LCPN hydrogel can significantly enhance cell proliferation, migration and antioxidant capacity, which is conducive to accelerated wound healing. In vitro and in vivo experiments have shown that LCPN hydrogel has excellent biocompatibility and the ability to promote wound healing. Therefore, the prepared multifunctional hydrogel is expected to be used as a novel dressing to accelerate wound healing.

Simultaneous efficient evaporation and stable electricity generation enabled by a wooden evaporator based on composite photothermal effect

The current solar interfacial evaporators have limited evaporation performance due to their single photothermal mechanism, insufficient light utilization, and improper heat management. Therefore, a novel approach involving polypyrrole (PPy) and Ag nanoparticles (AgNPs) modified wooden evaporator (AgPW) using an in-situ polymerization and growth method was proposed for efficient and sustainable freshwater purification. The composite photothermal effect of PPy and AgNPs led to a significantly enhanced light absorption capacity and superior photothermal conversion efficiency in a wide spectrum range, which coupled with the rapid water transport capacity conferred by the regular vertical channels and superior hydrophilicity of the delignified wood, resulted in remarkable evaporation performance through the coordinated regulation of thermal and water management. The optimized AgPW50 achieved an evaporation rate of up to 2.04 kg m−2 h−1 and an evaporation efficiency of 90.7 % under 1 kW m−2 irradiation. Importantly, this evaporator was highly salt resistant and long-term desalination stability, and can also be extended to the purification of various types of wastewaters while converting the released waste heat into stable electricity generation. The innovative Ag/PPy wooden evaporator integrates biomass resources with solar energy utilization, demonstrating an environmentally friendly, efficient and cost-effective strategy for seawater desalination and energy production, providing a new sustainable development pathway to solve the challenge of balancing water security and energy consumption.

Strong light-trapping probes with high antibody activity for sensitive detecting FB1 by “turn-on” lateral flow immunoassay

Due to the insufficient chromaticity, traditional Au nanoparticles (AuNPs) are usually unsatisfactory in the lateral flow immunoassay (LFIA) for tracing targets. Polypyrrole nanoparticles (PPyNPs), known for their excellent optical properties, have a limited chemical surface, which is unsuitable for use in LFIA. PPyNPs@metal-phenolic materials (PMNPs) were designed to break the restriction, which were then applied in fluorescence quenching LFIA to detect fumonisin B1 (FB1). PMNPs, as an efficient fluorescence quencher, with strong absorption in the ultraviolet–visible region, had the molar extinction coefficient of 2.47 × 1011 M−1 cm−1 and 1.86 × 1011 M−1 cm−1 at 335 nm and 620 nm. Meanwhile, the quenching constant of PMNPs was 2.30 × 10−10, 23.6-fold higher than that of AuNPs. After the surface modification with the Au-TA structure, PMNPs exhibited higher hydrophilicity than PPyNPs, making them more favorable to antibody binding. Compared with AuNPs-mAb and PPyNPs-mAb, the PMNPs-mAb had a higher affinity constant and lower equilibrium dissociation constant. The visual limit of detection (vLOD) and LOD of the “turn-on” LFIA based on PMNPs were 25 ng mL−1 and 1.58 ng mL−1, which were 20-fold and 4.82-fold lower than that of AuNPs-LFIA, respectively. Furthermore, the method demonstrated satisfactory recoveries in detecting FB1 in food samples, confirmed by LC-MS.

Development of folate-conjugated polypyrrole nanoparticles incorporated with nitrogen-doped carbon quantum dots for targeted bioimaging and photothermal therapy

PPy nanoparticles are widely employed as PTT agents, because of their exceptional near-infrared absorption properties. Nonetheless, the efficacy of PTT with PPy nanoparticles is hindered by a challenge, specifically, a lack of precise targeting. In this study, a PTT imaging agent was developed by combining NCQDs having bright green fluorescent properties with PPy nanoparticles along with the masking of folic acid to overcome the challenge of targeting. The synthesized PPy:NCQDs:FA nanocomposite, characterized by extraordinary photothermal property, was utilized for imaging of folate receptor positive (FA+) MCF-7 cancer cells through the emission of green fluorescence by NCQDs incorporated within the nanocomposite. Additionally, these nanoparticles demonstrated a good level of cell viability, exceeding 82 %, even at a concentration of 600 μg mL−1. Even the in vivo toxicity inspection of the nanocomposite exemplified no observed acute toxicity at experimental dosages of 1 and 3 mg per kg body weight. By subjecting MCF-7 cells, inoculated with 100 μg mL−1 of nanocomposite, to NIR laser irradiation for 5 min, a significant decline in cell viability was witnessed, establishing the photothermal therapeutic potency of the nanocomposite. The death of cancer cells induced by nanocomposite was verified through MTT assay, imaging of cells by NCQDs alone, with nanocomposite, and by live/dead cell Calcein AM/PI staining assay. Quantification of induced apoptosis post-laser treatment is conducted through staining with Annexin V-FITC/PI. These findings establish potential use of PPy:NCQDs:FA nanocomposite as versatile theranostic agents, capable of targeted bioimaging and treatment for cancer cells exhibiting folate receptors.

Preparation and Electrochromic Properties of MnO2/PPy Composite Films with Coral-like Structures.

MnO2/polypyrrole (PPy) composite films were deposited on fluorine-doped tin oxide (FTO) conductive glasses by a two-step wet-chemical method, including electrochemical deposition and chemical bath deposition (CBD). The porous MnO2 films were first grown on FTO glasses by an electrodeposition method. Second, polypyrrole nanoparticles were polymerized by the oxidation-reduction reaction between MnO2 and pyrrole, using the presynthesized MnO2 as the skeleton. Then, MnO2/PPy composite films with coral-like structures were obtained. The electrochemical and electrochromic (EC) properties of the prepared films were investigated. The results show that, compared to the single MnO2 or PPy film, the MnO2/PPy composite film has a larger optical modulation (67.3% at a wavelength of 900 nm), faster response times (4 s for coloration and 3 s for bleaching), and a higher coloration efficiency (218.16 cm2·C-1). The high coloration efficiency attests to the exceptional performance of the composite film in converting electrical signals into vivid color changes. The electrochemical stability test results show that the composite film maintains a stable EC performance after 200 coloration/bleaching cycles. The coral-like structures of the composite film are responsible for the better EC properties.

Biocompatible supercapacitor engineered from marine collagen impregnated with polypyrrole and tungsten disulfide

There is an urgent demand for highly stable energy storage systems that are biocompatible, environmentally friendly, and made from affordable, sustainable materials. Research on biologically sourced materials as green energy storage devices such as supercapacitor (SC) technologies are emerging, but they are often expensive, complicated to manufacture, and fail to meet the required performance levels. This article presents a simple and innovative method to fabricate a human skin comfortable SC electrode using collagen extracted from hoki (Macruronus novaezelandiae) fish skin. Polypyrrole and tungsten disulfide nanoparticles were incorporated into the collagen matrix via early wetness impregnation to provide the required electrical properties. Electrochemical investigations revealed that the areal capacitance of the composite material was 348 mF cm−2 and cyclic testing showed that the capacitance retention is 98 % after 50,000 cycles. The collagen-based composite demonstrated excellent biocompatibility to HEK293 cells grown over a 1-week period. This novel technique for producing biodegradable and biocompatible SC electrodes from renewable source paves opportunities to utilize other sources of biomaterials for smart electronic applications.

Robust Transparent Photothermal Omniphobic Coating for Efficient Anti/Deicing and Antifogging.

Icing and fogging on optical material surfaces bring various problems in daily life. Recently, some photothermal coatings have been reported to prevent the condensation or freeze of water droplets by increasing the surface temperature. However, it is a great challenge to apply them in practical conditions due to their opaqueness and poor mechanical wear-resistant property. In this work, we constructed a robust transparent photothermal omniphobic coating with a simple dip-coating technique. In the coating system, photothermal polypyrrole nanoparticles are introduced into inorganic silica networks, and then polydimethylsiloxane (PDMS) brushes were grafted on the inorganic silica layer to endow the surface with omniphobicity and stain resistance. The transparency and photothermal capacity of the coating can be regulated by the deposition times of the coating. In addition, the coating has an excellent anti/deicing property and reduces ice adhesion obviously due to the existence of "liquid-like" PDMS brushes. More importantly, the coating presents outstanding mechanical wear-resistant and self-lubricating properties that can endure several thousand friction cycles without performance loss. The mechanically robust photothermal omniphobic coating gives a feasible approach to anti-icing and antifogging of transparent substrates under sunlight irradiation.

Poly(lactic acid)/polycaprolactone-based self-programmed photothermal responsive shape memory polymers

Shape memory polymers, based on their unique property that they can automatically revert to their original shape after deformation when subjected to external stimuli, have shown great application prospects and practical value in many fields such as aerospace, automotive and biomedical in recent years. In this study, poly(lactic acid) (PLA)/polycaprolactone (PCL) is used as a substrate, and a graft product, PLA-g-GMA, is prepared by grafting glycidyl methacrylate (GMA) onto PLA as a compatibilizer, and then polymer substrates are prepared by melt extrusion. Then, light-responsive shape memory composites are prepared by loading polypyrrole (PPy) nanoparticles with photothermal conversion functionality into the PLA/PCL substrate, and PPy-coated NdFeB (PPy@NdFeB) is used as the functional phase to prepare auto-responsive shape memory polymers that can be programmed automatically. Among them, the PLA/PCL/PPy composites show shape recovery rate (Rr) and shape fixation rate (Rf) of 81.11% and 98.87%, respectively, at a strain of 85.27% under the programming conditions of a deformation temperature of 65 °C and a stress of 2.14 MPa. The PLA/PCL/PPy@NdFeB composite material, in addition to excellent double and triple shape memory behavior, also has obvious magnetic properties, which can be used to carry out self-programmed temporary shapes. This research aims to solve the limitations of temperature-responsive shape memory polymers in a single stimulus response mode, broaden their application scope, further promote the development of shape memory polymers, and provide realistic guidance for the field of 4D printing.

Electrochemiluminescence Immunosensor for Alpha-Fetoprotein Based on Polypyrrole-Luminol Nanoparticles

The study of luminol electrochemiluminescence (ECL) is commonly conducted in alkaline solutions. However, many substances, especially biomolecules, are only stable in neutral or weakly acidic media. In this study, a sensitive ECL immunosensor was developed using polypyrrole-luminol (PPY-Lu) nanoparticles for the determination of alpha-fetoprotein (AFP) in a neutral buffer. Polypyrrole (PPY) nanoparticles were synthesized by chemical oxidation. Subsequently, luminol was attached to the PPY nanoparticles via electrostatic interaction, resulting in the formation of the desired nanoparticles which exhibited strong and stable electrochemiluminescence in neutral solution. Furthermore, the PPY-Lu nanoparticles have abundant amino groups suitable for immobilizing biomolecules. An ECL immunosensor for AFP was fabricated by immobilizing anti-AFP on the PPY-Lu-modified electrode surface. The electrochemiluminescence decreased when AFP was captured. The immunosensor exhibited a linear range from 1.0 × 10−11 to 1.0 × 10−6 mg/mL with a low detection limit of 8.5 × 10−12 mg/mL and excellent specificity, reproducibility, and long-term stability. This designed immunosensor provides a new method for the determination of biomarkers in clinical analysis.

Wintersweet-like Nanohybrids of Titanium-doped Cerium Vanadate Loaded with Polypyrrole for Tumor Theranostic.

Compromises between enhanced on-targeting reactivity and precise real-time monitoring in the tumor microenvironment (TME) are the main roadblocks for catalytic cancer therapy. The hallmark of a high level of hydrogen peroxide (H2O2) and acidic extracellular environment of the hypoxia solid tumor can underpin therapeutic and tracking performance. Herein, this work provides an activatable wintersweet-like nanohybrid consisting of titanium (Ti) doped cerium vanadate nanorods with the modification of polypyrrole (PPy)nanoparticles (CeVO4-Ti@PPy) for combinatorial therapies of breast carcinoma. The Ti dopants in the size-controllable CeVO4 nanorods lower the energy barrier (0.5eV) of the rate-determining steps and elaborate peroxidase-like (POD-like)activities to improve the generation of toxic hydroxyl radical (·OH) according to the density functional theory (DFT) calculation. The multiple enzyme-like activities, including the intrinsic glutathione peroxidase (GPx) and catalase (CAT), achieve a record-high therapeutic efficiency. Coupling this oxidative stress with the photothermal effects of PPy enables enhanced catalytic tumor necrosis. The exterior PPy heterogeneous structure can be further doped with protons in the local acidic environment to intensify photoacoustic signals, allowing the non-invasive accurate tracking of tumors. The theranostic performance displayed negligible attenuated signals in near-infrared (NIR) windows. This organic-inorganic nanohybrid with a heterogeneous structure provides the potential to improve the overall outcomes of catalytic therapy.

Preparation and characterization of hybrid polypyrrole nanoparticles as a conducting polymer with controllable size

Hybrid polypyrrole (PPy) nanoparticles were prepared using a low-temperature oxidative polymerization process in an acidic solution with polyethyleneimine (PEI) as a template and amine source. The results showed that the nanoparticles have an amorphous structure in the X-ray diffractogram and exhibited good dispersibility in water, uniform size, and a specific conductivity ranging from 0.1 to 6.9 S/cm. The particle size could be tuned from 85 to 300 nm by varying the reactant concentration. Undoping the samples with sodium hydroxide (NaOH) solution altered the optical absorption properties and surface roughness of the particles. However, it did not affect the particle size. The nanoparticles also exhibited optical sensing properties based on their UV–vis absorption changes with the pH. Moreover, nanoparticles could have potential applications in gene delivery and bio-adsorption for contaminant removal. This work demonstrates a simple and effective method for preparing hybrid polypyrrole nanoparticles with controllable size, dispersibility, and conductivity for various nanotechnology, biotechnology, and environmental engineering purposes.

A flexible sanded cotton fabric coated with Au@polypyrrole for seawater desalination

Nowadays, freshwater has increasingly become a scarce resource. Seawater distillation is limited due to the high costs and low conversion rates. Herein, a functional cotton fabric with significant photothermal properties was prepared through a simple sanding treatment, followed by a polypyrrole (PPy) and Au nanoparticles coating. The functional materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis. The solar water evaporation measurements showed that the sanded cotton fabrics coated Au@PPy exhibited excellent photothermal conversion with an energy efficiency being 93.38 % for solar-steam generation under 1.0 sun irradiation, corresponding to a water evaporation rate of 1.33 kg·m−2·h−1. Moreover, the coated fabric also exhibited excellent tolerance to acidic and alkaline conditions.

Development and characterization of 3D-printed electroconductive pHEMA-co-MAA NP-laden hydrogels for tissue engineering

AbstractTissue engineering (TE) continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration. In this study, we developed a poly(2-hydroxyethyl methacrylate-co-methacrylic acid) (pHEMA-co-MAA) based hydrogel loaded with newly synthesized conductive poly(3,4-ethylene-dioxythiophene) (PEDOT) and polypyrrole (PPy) nanoparticles (NPs), and subsequently processed these hydrogels into tissue engineered constructs via three-dimensional (3D) printing. The presence of the NPs was critical as they altered the rheological properties during printing. However, all samples exhibited suitable shear thinning properties, allowing for the development of an optimized processing window for 3D printing. Samples were 3D printed into pre-determined disk-shaped configurations of 2 and 10 mm in height and diameter, respectively. We observed that the NPs disrupted the gel crosslinking efficiencies, leading to shorter degradation times and compressive mechanical properties ranging between 450 and 550 kPa. The conductivity of the printed hydrogels increased along with the NP concentration to (5.10±0.37)×10−7 S/cm. In vitro studies with cortical astrocyte cell cultures demonstrated that exposure to the pHEMA-co-MAA NP hydrogels yielded high cellular viability and proliferation rates. Finally, hydrogel antimicrobial studies with staphylococcus epidermidis bacteria revealed that the developed hydrogels affected bacterial growth. Taken together, these materials show promise for various TE strategies. Graphic abstract

Rational design of CdS-enwrapped polypyrrole nanoparticles for wastewater treatment: removal of hazardous pollutants in aqueous solutions.

The modern world requires a chemical industry that can run at low production costs while producing high-quality products with minimal environmental impact. The development of environmentally friendly, cost-effective, and efficient wastewater treatment materials remains a majorproblem for the sustainable approach. We prepared nanoscale cadmium sulfide (CdS)-enwrapped polypyrrole (PPy) polymer composites for degradation of organic pollutants. The prepared CdS@PPy nanocomposites were characterized by powder X-ray diffraction, scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible(UV) absorption spectroscopy, indicating proper intercalation between CdS and PPy. Consequently, the catalytic efficiency of the synthesized hybrid nanocomposites was analyzed through the degradation of methylene blue (MB) and rhodamine B (Rh B) under visible light irradiation. The measured degradation efficiency of the dye solutions under the photolysis process is about 18% and 23% for MB and Rh B dye, respectively. Furthermore, the recycle test result concludes that the CdS@PPy composite exhibits 91% and 89% of MB and Rh B dye degradation efficiency even at the 4th cycle, respectively. The positive synergistic impact of CdS and PPymay be the result of effective photocatalytic degradation of MB and RhB.

A Peptide‐Polyphenol Coated Polypyrrole Nanoparticle for Synergetic Attenuation of Aggregation and Cytotoxicity of Amyloid‐β Fibrils

AbstractAmyloid‐β (Aβ) pathway is positioned as the center for Alzheimer's disease (AD) pathophysiology. Viable drugs targeting Aβ pathway are developed with promising outcomes. Meanwhile, most current approaches are focused on the inhibition of Aβ fibrillization or elimination of Aβ plaques by immunotherapeutic strategies. Here, near‐infrared (NIR) photothermal polypyrrole nanoparticles coated with peptide‐polyphenol are developed to both inhibit the Aβ fibrillization and disaggregate Aβ fibrils synergistically. Aβ fibrillization is obviously inhibited after being treated with the photothermal polypyrrole nanoparticles. Besides inhibition of Aβ fibrillization, the amount of Aβ fibrils is gradually reduced with time by 38.0% when co‐incubated with polypyrrole nanoparticles, indicating desired disaggregation capability against Aβ fibrils. In addition, faster and more disaggregation of Aβ fibrils is observed when irradiation by NIR light. Meanwhile, cellular studies also verified that this nanoparticle is able to effectively reduce the cytotoxicity of Aβ fibrils toward PC12 cells through disaggregating toxic Aβ aggregates and maintaining integral membrane structure. Hence, this peptide‐polyphenol‐coated NIR photothermal polypyrrole nanoparticle provides a new perspective for the inhibition of Aβ fibrillization and disaggregation of Aβ fibrils, which can serve as a promising approach for anti‐amyloidosis.