Nanoparticle-assisted tubulin assembly is environment dependent.

Nanomaterials acquire a biomolecular corona upon introduction to biological media, leading to biological transformations such as changes in protein function, unmasking of epitopes, and protein fibrilization. Ex vivo studies to investigate the effect of nanoparticles on protein-protein interactions are typically performed in buffer and are rarely measured quantitatively in live cells. Here, we measure the differential effect of silica nanoparticles on protein association in vitro vs. in mammalian cells. BtubA and BtubB are a pair of bacterial tubulin proteins identified in Prosthecobacter strains that self-assemble like eukaryotic tubulin, first into dimers and then into microtubules in vitro or in vivo. Förster resonance energy transfer labeling of each of the Btub monomers with a donor (mEGFP) and acceptor (mRuby3) fluorescent protein provides a quantitative tool to measure their binding interactions in the presence of unfunctionalized silica nanoparticles in buffer and in cells using fluorescence spectroscopy and microscopy. We show that silica nanoparticles enhance BtubAB dimerization in buffer due to protein corona formation. However, these nanoparticles have little effect on bacterial tubulin self-assembly in the complex mammalian cellular environment. Thus, the effect of nanomaterials on protein-protein interactions may not be readily translated from the test tube to the cell in the absence of particle surface functionalization that can enable targeted protein-nanoparticle interactions to withstand competitive binding in the nanoparticle corona from other biomolecules.

Elucidating the formation of the uniform "glass-like" texture in dried-bonito during processing based on microstructure and protein properties.

Dried-bonito (Katsuobushi) exhibits a unique uniform "glass-like" texture after traditional smoke-drying. Herein, we developed a novel processing method for dried-bonito and elucidated the mechanism of transformation of loose muscle into a "glass-like" texture in terms of texture, microstructure, and protein properties. Our findings showed that the unfolding and aggregation of proteins after thermal induction was a key factor in shaping the "glass-like" texture in bonito muscle. During processing, myofibrils aggregated, the originally alternating thick and thin filaments contracted laterally and aligned into a straight line, and protein cross-linking increased. Secondary structural analysis revealed a reduction in unstable ß-turn content from 26.28% to 15.06%. Additionally, an increase in the content of SS bonds was observed, and the conformation changed from g-g-t to a stable g-g-g conformation, enhanced protein conformational stability. Taken together, our findings provide a theoretical basis for understanding the mechanism of formation of the uniform "glass-like" texture in dried-bonito.

"One for two" strategy to construct an organic-inorganic polymer colloid for flame-retardant modification of flax fabric and rigid polyurethane foam.

Polymeric materials such as fabric and foam have high flammability which limits their application in the field of fire protection. To this end, an organic-inorganic polymer colloid constructed from carboxymethyl chitosan and ammonium polyphosphate was used to improve the flame retardancy of flax fabric (FF) and rigid polyurethane foam (RPUF) based on a "one for two" strategy. The modification processes of FF and RPUF relied on pad-dry-cure method and UV-curing technology, respectively, and the modified FF and RPUF were severally designated as CMC/APP-FF and RFR-RPUF. Flame retardancy studies showed that CMC/APP-FF and RFR-RPUF exhibited limiting oxygen index values as high as 39.4 % and 42.6 %, respectively, and both achieved self-extinguishing when external ignition source was removed. Thermogravimetric analysis and cone calorimetry test confirmed that CMC/APP-FF and RFR-RPUF had good charring ability and demonstrated reduced peak heat release rate values of 90.1 % and 10.8 %, respectively, distinct from before they were modified. In addition, condensed phase analysis showed that after burning, CMC/APP-FF became an integration char structure, whereas RFR-RPUF turned into a sandwiched char structure. In summary, the "one for two" strategy reported in this work provides new insights for the economical fabrication of flame-retardant polymeric materials.

Occurrence and Flow Behavior for Oil Transport in Mixed Wetting Nanoscale Shale Bedding Fractures.

Shale reservoirs are characterized by an abundance of nanoscale porosities and microfractures. The states of fluid occurrence and flow behaviors within nanoconfined spaces necessitate novel research approaches, as traditional percolation mathematical models are inadequate for accurately depicting these phenomena. This study takes the Gulong shale reservoir in China as the subject of its research. Initially, the unique mixed wetting characteristics of the Gulong shale reservoir are examined and characterized using actual micropore images. Subsequently, the occurrence and flow behavior of oil within the nanoscale bedding fractures under various wettability scenarios are described through a combination of microscopic pore image and molecular dynamics simulations. Ultimately, a mathematical model is established that depicts the velocity distribution of oil and its apparent permeability. This study findings indicate that when the scale of the shale bedding fractures is less than 100 nm, the impact of the nanoconfinement effect is significant and cannot be overlooked. In this scenario, the state of oil occurrence and its flow behavior are influenced by the initial oil-wet surface area on the mixed wetting walls. The study quantifies the velocity and density distribution of oil in mixed wetting nanoscale shale bedding fractures through a mathematical model, providing a crucial theoretical basis for upscaling from the nanoscale to the macroscale.

Changes in stresses sensitivity of ohmic heating-induced sublethally injured Staphylococcus aureus during repair: Potential mechanisms at the cellular and molecular levels.

Ohmic heating (OH), an emerging food processing technology employed in the food processing industry, raises potential food safety concerns due to the recovery of sublethally injured pathogens such as Staphylococcus aureus (S. aureus). In the present study, sensitivity to various stress conditions and the changes in cellular-related factors of OH-injured S. aureus during repair were investigated. The results indicated that liquid media differences (nutrient broth (NB), phosphate-buffered saline (PBS), milk, and cucumber juice) affected the recovery process of injured cells. Nutrient enrichment determines the bacterial repair rate, and the rates of repair for these media were milk > NB > cucumber juice > PBS. The sensitivity of injured cells to various stressors, including different acids, temperature, nisin, simulated gastric fluid, and bile salt, increased during the injury phase and subsequently diminished upon repair. Additionally, the intracellular ATP content, enzyme activities (Na+/K+-ATPase, Ca2+/Mg2+-ATPase, and T-ATPase) and ion concentrations (Mg2+, K+, and Ca2+) gradually increased during repair. After 5 h of repair, the intracellular substances content of cell's was significantly higher than that of the injured bacteria without repair, while some indicators (e.g., Na+/K+-ATPase, K+, and Ca2+) were not restored to the untreated level. The results of this study indicated that OH-injured S. aureus exhibited strengthened resistance post-recovery, potentially due to the restoration of cellular structures. These findings have implications for optimizing food storage conditions and advancing OH processes in the food industry.

Synergism of Light-Induced [4 + 4] Cycloaddition and Electron Transfer Toward Switchable Photoluminescence and Single-Molecule Magnet Behavior in a Dy4 Cubane.

Molecular materials possessing switchable magneto-optical properties are of great interest due to their potential applications in spintronics and molecular devices. However, switching their photoluminescence (PL) and single-molecule magnet (SMM) behavior via light-induced structural changes still constitutes a formidable challenge. Here, a series of cubane structures were synthesized via self-assembly of 9-anthracene carboxylic acid (HAC) and rare-earth ions. All complexes exhibited obvious photochromic phenomena and complete PL quenching upon Xe lamp irradiation, which were realized via the synergistic effect of photogenerated radicals and [4 + 4] photocycloaddition of the AC components. The quenched PL showed the largest fluorescence intensity change (99.72%) in electron-transfer photochromic materials. A reversible decoloration process was realized via mechanical grinding, which is unexpectedly in the electron-transfer photochromic materials. Importantly, an SMM behavior of the Dy analog was observed after room-temperature irradiation due to the photocycloaddition of AC ligands and the photogenerated stable radicals changed the electrostatic ligand field and magnetic coupling. Moreover, based on the remarkably photochromic and photoluminescent properties of these compounds, 2 demos were applied to support their application in information anti-counterfeiting and inkless printing. This work, for the first time utilizing the simultaneous modulation of photocycloaddition and photogenerated radicals in one system, realizes complete PL quenching and light-induced SMM behavior, providing a dynamical switch for the construction of multifunctional polymorphic materials with optical response and optical storage devices.

Ultraflexible Ultrathin 3D/1D Hierarchical Interpenetrating Ni-MOF/CNT Buckypaper Composites: Microstructures and Microwave Absorption Properties.

Metal-organic frameworks (MOFs) have attracted attention due to their designable structures. However, recently reported MOF microwave-absorbing materials (MAMs) are dominated by powders. It remains a challenge to design MOF/carbon nanotube (CNT) composite structures that combine the mechanical properties of self-supporting flexibility with excellent microwave absorption. This work involves the hydrothermal approach to grow Ni-MOF of different microstructures in situ on the CNT monofilament by adjusting the molar ratio of nickel ions to organic ligands. Subsequently, an ultraflexible self-supporting Ni-MOF/CNT buckypaper (BP) is obtained by directional gas pressure filtration technology. The BP porous skeleton and the Ni-MOF with a unique porous structure provide effective impedance matching. The CNTs contribute to the conduction loss, the cross-scale heterogeneous interface generated by Ni-MOF/CNT BP provides rich interfacial polarization loss, and the porous structure complicates the microwave propagation path. All factors work together to give Ni-MOF/CNT BP an excellent microwave absorption capacity. The minimum reflection losses of Ni-MOF/CNT BPs decorated with granular-, hollow porous prism-, and porous prism-shaped Ni-MOFs reach -50.8, -57.8, and -43.3 dB, respectively. The corresponding effective absorption bandwidths are 4.5, 6.3, and 4.8 GHz, respectively. Furthermore, BPs show remarkable flexibility as they can be wound hundreds of times around a glass rod with a diameter of 4 mm without structural damage. This work presents a new concept for creating ultraflexible self-supported MOF-based MAMs with hierarchical interpenetrating porous structures, with potential application advantages in the field of flexible electronics.

Atomically Resolved Transition Pathways of Iron Redox.

The redox transition between iron and its oxides is of the utmost importance in heterogeneous catalysis, biological metabolism, and geological evolution. The structural characteristics of this reaction may vary based on surrounding environmental conditions, giving rise to diverse physical scenarios. In this study, we explore the atomic-scale transformation of nanosized Fe3O4 under ambient-pressure H2 gas using in-situ environmental transmission electron microscopy. Our results reveal that the internal solid-state reactions dominated by iron diffusion are coupled with the surface reactions involving gaseous O or H species. During reduction, we observe two competitive reduction pathways, namely Fe3O4 → FeO → Fe and Fe3O4 → Fe. An intermediate phase with vacancy ordering is observed during the disproportionation reaction of Fe2+ → Fe0 + Fe3+, which potentially alleviates stress and facilitates ion migration. As the temperature decreases, an oxidation process occurs in the presence of environmental H2O and trace amounts of O2. A direct oxidation of Fe to Fe3O4 occurs in the absence of the FeO phase, likely corresponding to a change in the water vapor content in the atmosphere. This work elucidates a full dynamical scenario of iron redox under realistic conditions, which is critical for unraveling the intricate mechanisms governing the solid-solid and solid-gas reactions.

Presurgical structural imaging and clinical outcome in combined bed nucleus of the stria terminalis-nucleus accumbens deep brain stimulation for treatment-resistant depression.

Background: Structural imaging holds great potential for precise targeting and stimulation for deep brain stimulation (DBS). The anatomical information it provides may serve as potential biomarkers for predicting the efficacy of DBS in treatment-resistant depression (TRD). Aims: The primary aim is to identify preoperative imaging biomarkers that correlate with the efficacy of DBS in patients with TRD. Methods: Preoperative imaging parameters were estimated and correlated with the 6-month clinical outcome of patients with TRD receiving combined bed nucleus of the stria terminalis (BNST)-nucleus accumbens (NAc) DBS. White matter (WM) properties were extracted and compared between the response/non-response and remission/non-remission groups. Structural connectome was constructed and analysed using graph theory. Distances of the volume of activated tissue (VAT) to the main modulating tracts were also estimated to evaluate the correlations. Results: Differences in fibre bundle properties of tracts, including superior thalamic radiation and reticulospinal tract, were observed between the remission and non-remission groups. Distance of the centre of the VAT to tracts connecting the ventral tegmental area and the anterior limb of internal capsule on the left side varied between the remission and non-remission groups (p=0.010, t=3.07). The normalised clustering coefficient (γ) and the small-world property (σ) in graph analysis correlated with the symptom improvement after the correction of age. Conclusions: Presurgical structural alterations in WM tracts connecting the frontal area with subcortical regions, as well as the distance of the VAT to the modulating tracts, may influence the clinical outcome of BNST-NAc DBS. These findings provide potential imaging biomarkers for the DBS treatment for patients with TRD.

3D embedded bioprinting of large-scale intestine with complex structural organization and blood capillaries.

Accurate reproduction of human intestinal structure and functionin vitrois of great significance for understanding the development and disease occurrence of the gut. However, mostin vitrostudies are often confined to 2D models, 2.5D organ chips or 3D organoids, which cannot fully recapitulate the tissue architecture, microenvironment and cell compartmentalization foundin vivo. Herein, a centimeter-scale intestine tissue that contains intestinal features, such as hollow tubular structure, capillaries and tightly connected epithelium with invivo-likering folds, crypt-villi, and microvilli is constructed by 3D embedding bioprinting. In our strategy, a novel photocurable bioink composed of methacrylated gelatin, methacrylated sodium alginate and poly (ethylene glycol) diacrylate is developed for the fabrication of intestinal model. The Caco-2 cells implanted in the lumen are induced by the topological structures of the model to derive microvilli, crypt-villi, and tight junctions, simulating the intestinal epithelial barrier. The human umbilical vein endothelial cells encapsulated within the model gradually form microvessels, mimicking the dense capillary network in the intestine. This intestine-like tissue, which closely resembles the structure and cell arrangement of the human gut, can act as a platform to predict the therapeutic and toxic side effects of new drugs on the intestine.

Manipulating the Rate and Overpotential for Electrochemical Water Oxidation: Mechanistic Insights for Cobalt Catalysts Bearing Noninnocent Bis(benzimidazole)pyrazolide Ligands.

Electrochemical water oxidation is known as the anodic reaction of water splitting. Efficient design and earth-abundant electrocatalysts are crucial to this process. Herein, we report a family of catalysts (1-3) bearing bis(benzimidazole)pyrazolide ligands (H 2 L1-H 2 L3). H 2 L3 contains electron-donating substituents and noninnocent components, resulting in catalyst 3 exhibiting unique performance. Kinetic studies show first-order kinetic dependence on [3] and [H2O] under neutral and alkaline conditions. In contrast to previously reported catalyst 1, catalyst 3 exhibits an insignificant kinetic isotope effect of 1.25 and zero-order dependence on [NaOH]. Based on various spectroscopic methods and computational findings, the L3Co2 III(µ-OH) species is proposed to be the catalyst resting state and the nucleophilic attack of water on this species is identified as the turnover-limiting step of the catalytic reaction. Computational studies provided insights into how the interplay between the electronic effect and ligand noninnocence results in catalyst 3 acting via a different reaction mechanism. The variation in the turnover-limiting step and catalytic potentials of species 1-3 leads to their catalytic rates being independent of the overpotential, as evidenced by Eyring analysis. Overall, we demonstrate how ligand design may be utilized to retain good water oxidation activity at low overpotentials.

Bacterial evolution in Biofiltration of drinking water treatment plant: Different response of phage and plasmid to varied water sources.

Biofiltration in drinking water treatment (BDWT) are popular as it holds promise as an alternative to chemical treatments, yet our understanding of the key drivers and trends underlying bacterial evolution within this process remains limited. While plasmids and phages are recognized as the main vectors of horizontal gene transfer (HGT), their roles in shaping bacterial evolution in BDWT remain largely unknown. Here we leverage global metagenomic data to unravel the primary forces driving bacterial evolution in BDWT. Our results revealed that the primary vector of HGT varies depending on the type of source water (groundwater and surface water). Both plasmids and phages accelerated bacterial evolution in BDWT by enhancing genetic diversity within species, but they drove contrasting evolutionary trends in functional redundancy in different source water types. Specifically, trends towards and away from functional redundancy (indicated as gene-protein ratio) were observed in surface-water and groundwater biofilters, respectively. Virulent phages drove bacterial evolution through synergistic interactions with bacterial species capable of natural transformation and with certain natural compounds that disrupt bacterial cytoplasmic membranes. Genes relating to water purification (such as Mn(II)-oxidizing genes), microbial risks (antibiotic resistance genes), and chemical risk (polycyclic aromatic hydrocarbons) were enriched via HGT in BDWT, highlighting the necessity for heighted focus on these useful and risky objects. Overall, these discoveries enhance our understanding of bacterial evolution in BDWT and have implications for the optimization of water treatment strategies.

Protocol for the detection of mechanosensitive response of proteins in cultured cells under compressive stress.

Here, we present a protocol to detect mechanosensitive responses of proteins in cells under compressive stress. We describe steps for preparing elastic gels to compress cells grown on an imaging chamber. We then detail procedures for imaging proteins at the cell cortex using high-resolution confocal microscopy. The protocol can be applied to examine the mechanosensitive response of fluorescently tagged proteins in mitotic cells or round interphase cells adhering to the imaging surface. For complete details on the use and execution of this protocol, please refer to Wang et al.1.

The causal relationship between 5 serum lipid parameters and diabetic nephropathy: a Mendelian randomization study.

Background: Serum lipids were found to be correlated with chronic kidney disease and cardiovascular disease. Here, we aimed to research the potential causal associations between five serum lipid parameters and the risk of diabetic nephropathy using several Mendelian Randomization methods. Methods: Genetic data was obtained from the UK Biobank datasets. Causal effects were estimated using multiple MR methods. Heterogeneity and pleiotropy tests were performed. Results: MR analysis revealed that HDL-C and TG exhibited causal associations with diabetic nephropathy (P<0.05). Similar trends were not observed for other lipid parameters. Conclusions: Our research has suggested links between HDL-C, TG and diabetic nephropathy. The findings could contribute to further elucidation of the disease etiology. Strengths and limitations of this study: This article only uses Mendel randomization method to analyze the relationship between blood lipids and diabetes nephropathy, which is more convincing when combined with population data.

Comparing the accuracy of four machine learning models in predicting type 2 diabetes onset within the Chinese population: a retrospective study.

OBJECTIVE: To evaluate the effectiveness of machine learning (ML) models in predicting 5-year type 2 diabetes mellitus (T2DM) risk within the Chinese population by retrospectively analyzing annual health checkup records. METHODS: We included 46,247 patients (32,372 and 13,875 in training and validation sets, respectively) from a national health checkup center database. Univariate and multivariate Cox analyses were performed to identify factors influencing T2DM risk. Extreme Gradient Boosting (XGBoost), support vector machine (SVM), logistic regression (LR), and random forest (RF) models were trained to predict 5-year T2DM risk. Model performances were analyzed using receiver operating characteristic (ROC) curves for discrimination and calibration plots for prediction accuracy. RESULTS: Key variables included fasting plasma glucose, age, and sedentary time. The LR model showed good accuracy with respective areas under the ROC (AUCs) of 0.914 and 0.913 in training and validation sets; the RF model exhibited favorable AUCs of 0.998 and 0.838. In calibration analysis, the LR model displayed good fit for low-risk patients; the RF model exhibited satisfactory fit for low- and high-risk patients. CONCLUSIONS: LR and RF models can effectively predict T2DM risk in the Chinese population. These models may help identify high-risk patients and guide interventions to prevent complications and disabilities.

Ultrasound induced grain refinement of crystallization in evaporative saline droplets.

We investigate the effect of ultrasound on the evaporation and crystallization of sessile NaCl solution droplets which were positioned in traveling or standing wave ultrasound field. The experimental results indicated that the ultrasound field can significantly accelerate the evaporation rate of the sessile droplets and refine the crystal grains. By adjusting the distance between the sessile droplets and the ultrasound emitter, it is found that, in traveling wave ultrasound field, the sessile droplet evaporation time and the time for the appearance of NaCl grains exhibited a fluctuating increase as the droplet-emitter distance increased. While in the standing wave ultrasound, the sessile droplet evaporation rate increases with the increasing droplet-emitter distance. Overall, the traveling wave ultrasound field has a stronger effect on grain refinement of the sessile droplets than the standing wave ultrasound field. The grain refinement is attributed to the decrease of critical nucleation radius caused by ultrasound energy and the increase of the nucleation rate caused by the accelerated evaporation rate. In addition, the breakage of grains caused by ultrasonic cavitation would also lead to grain refinement.

Developing a Motion Sensor-Based Game to Support Frozen Shoulder Rehabilitation in Older Adults through a Participatory Design Approach.

Objective: Although some serious games have been developed for physical therapy, little work has been conducted through a participatory design approach. Therefore, a game prototype was developed, which involved related stakeholders in the design process. Materials and Methods: The iterative participatory design process was adopted with the input of 18 patients with frozen shoulder symptoms, 4 health professionals, 2 game designers, and 5 researchers in an iterative process to design, test, and evaluate the game prototype. In total, 17 patients participated in the interviews to explore their needs and desires for a serious game. The health professionals participated in the interviews to understand the medical requirement and experience pertaining to frozen shoulder and were included in the workshop to give feedback on the game prototype. At the conclusion of the iterative design process, a Kinect-based prototype game with three levels was used for a case study with one patient who was diagnosed with frozen shoulder and has been receiving medical treatment in the hospital. Results: Based on the outcomes derived from data collected among diverse stakeholders, the prototype game underwent iterative development by the team and was assessed by a participant with frozen shoulder symptoms. Findings revealed that the participant demonstrated enhanced shoulder mobility and a reduction in pain intensity, despite the lack of significant improvement for health-related quality of life. Nevertheless, the participant reported a positive experience with the prototype game. Conclusion: This study underscores the importance of involving diverse stakeholders in the development process to create more effective and user-centric serious games for rehabilitation. The participatory approach, exemplified by the prototype game, demonstrates potential improvements in both user experience and overall effectiveness during the rehabilitation process.

Children's consideration of motivation in evaluations of socially (un)mindful actions.

Previous research shows that both adults and children by 5 or 6 years of age appreciate socially mindful actions where one leaves a choice for others. However, less is known as to whether children consider motivations in their evaluations of socially (un)mindful actions. Here we investigated whether children and adults can spontaneously evaluate socially (un)mindful behaviors depending on contextual cues, specifically whether the actions happen in public or in private. We also investigated how children evaluate these actions when provided with explicit information on motivations. We presented 99 children (aged 6-11 years) and 99 adults in China with two characters performing the same socially mindful or unmindful behaviors. One character acted publicly, whereas the other acted privately. Participants were asked to compare the two characters first spontaneously and then again after explicit information on the characters' motivations was provided. We found that whereas adults spontaneously favor private socially mindful acts, children favor public socially mindful acts. Only after motivations were provided did children favor private socially mindful acts like adults. In addition, we found asymmetry in that motivation seems to matter more in evaluations of socially mindful actions than in evaluations of socially unmindful ones. These findings are the first to reveal children's consideration of motivations in their evaluations of socially mindful behaviors.

Warming-induced shifts in alpine soil microbiome: An ecosystem-scale study with environmental context-dependent insights.

Climate warming is a pressing global issue with substantial impacts on soil health and function. However, the influence of environmental context on the responses of soil microorganisms to warming remains largely elusive, particularly in alpine ecosystems. This study examined the responses of the soil microbiome to in situ experimental warming across three elevations (3850 m, 4100 m, and 4250 m) in the meadow of Gongga Mountain, eastern Tibetan Plateau. Our findings demonstrate that soil microbial diversity is highly resilient to warming, with significant impacts observed only at specific elevations. Furthermore, the influence of warming on the composition of the soil microbial community is also elevation-dependent, underscoring the importance of local environmental context in shaping microbial evolution in alpine soils under climate warming. Notably, we identified soil moisture at 3850 m and carbon-to-nitrogen ratio at 4250 m as indirect predictors regulating the responses of microbial diversity to warming at specific elevations. These findings underscore the paramount importance of considering pre-existing environmental conditions in predicting the response of alpine soil microbiomes to climate warming. Our study provides novel insights into the intricate interactions between climate warming, soil microbiome, and environmental context in alpine ecosystems, illuminating the complex mechanisms governing soil microbial ecology in these fragile and sensitive environments.

Nucleic acid aptamer-based electrochemical sensor for the detection of serum P-tau231 and the instant screening test of Alzheimer's disease.

The instant screening of patients with a tendency towards developing Alzheimer's disease (AD) is significant for providing preventive measures and treatment. However, the current imaging-based technology cannot meet the requirements in the early stage. Developing biosensor-based liquid biopsy technology could be overcoming this bottleneck problem. Herein, we developed a simple, low-cost, and sensitive electrochemical aptamer biosensor for detecting phosphorylated tau protein threonine 231 (P-tau231), the earliest and one of the most efficacious abnormally elevated biomarkers of AD. Gold nanoparticles (AuNPs) were electrochemically synthesized on a glassy carbon electrode as the transducer, exhibiting excellent conductivity, and were applied to amplify the electrochemical signal. A nucleic acid aptamer was designed as the receptor to capture the P-tau231 protein, specifically through the formation of an aptamer-antigen complex. The proposed biosensor showed excellent sensitivity in detecting P-tau 231, with a broad linear detection range from 10 to 107 pg/mL and a limit of detection (LOD) of 2.31 pg/mL. The recoveries of the biosensor in human serum ranged from 97.59 to 103.26%, demonstrating that the biosensor could be used in complex practical samples. In addition, the results showed that the developed biosensor has good repeatability, reproducibility, and stability, which provides a novel method for the early screening of AD.