查找使用阿拉丁产品的科研文献

A Simple Colorimetric Assay for Sensitive Cu2+ Detection Based on the Glutathione-Mediated Etching of MnO2 Nanosheets

Tang Shurong,Liu Qiao,Hu Jie,Chen Wei,An Fengping,Xu Hui,Song Hongbo,Wang Yi-Wei

In this paper, we developed a quick, economical and sensitive colorimetric strategy for copper ions (Cu2+) quantification via the redox response of MnO2 nanosheets with glutathione (GSH). This reaction consumed MnO2 nanosheets, which acted as a catalyst for the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to a blue product (oxTMB). In the presence of Cu2+, the GSH was catalyzed to GSSG (oxidized glutathione), and the solution changed from colorless to deep blue. Under the optimum conditions, the absorption signal of the oxidized product (oxTMB) became proportional to Cu2+ concentration in the range from 10 to 300 nM with a detection limit of 6.9 nM. This detection system showed high specificity for Cu2+. Moreover, the system has been efficaciously implemented for Cu2+ detection in actual tap water samples. The layered-nanostructures of MnO2 nanosheets make it possess high chemical and thermal stability. TMB can be quickly oxidized within 10 min by the catalyzing of MnO2 nanosheets with high oxidase-like activity. There is no need of expensive reagents, additional H2O2 and complicated modification processes during the colorimetric assay. Therefore, the strategy primarily based on MnO2 nanosheets is promising for real-time, rapid and highly sensitive detection of Cu2+ under practical conditions.

Dual-Regulated Biomimetic Nanocomposites For Promoted Tumor Photodynamic Immunotherapy

Li Liao,Yufei Liu,Xianhai Li,Zewei Jiang,Zhijie Jiang,Jing Yao

Effective tumor immunotherapy is hindered by an immunosuppressive tumor microenvironment (TME), especially in triple-negative breast cancer. Though phototherapy could induce immunogenic cell death (ICD) to increase antitumor immunity, the simultaneous upregulation of indoleamine 2,3-dioxygenase (IDO) induces the negative immunomodulatory effect termed as the “immune-metabolism” loop to compromise immunotherapeutic efficacy. Herein, we developed IMMGP consisting of biomimetic IND-Mn@PM (IDP) and ICG-MnO2@PM (IMP), which combines the phototherapy-induced ICD and metabolic reprogramming to solve the dilemma. During the light-on phase, IMP effectively kills cancer cells with potent photodynamic ROS generation with the assistance of MnO2-produced oxygen and induces ICD to reverse the immunosuppressive TME. In the light-off phase, Mn2+ (from IDP and MnO2-based redox reaction) elicits a Fenton-like reaction to relay ROS generation, which is further orchestrated with continuous exhaustion of intratumoral GSH by the conversion of Mn3+ to Mn2+, and promotes dendritic cell maturation. Moreover, the released indoximod (IND) downregulated IDO to inhibit kynurenine metabolism, which reinvigorates T cell-mediated antitumor immunity. Collectively, IMMGP amplifies the immune response by breaking the “immune-metabolism” loop and sustaining the “immunologically hot” state after phototherapy, thus leading to nearly complete tumor inhibition (94.25%). Thus, IMMGP-mediated dual-phase photodynamic immunotherapy offers a novel approach in cancer nanomedicine.

Machine-Learning-Assisted CRISPR/Cas12a Biosensors for Monitoring Organophosphorus Pesticide Degradation

Jiaqi Xue,Kang Mao,Zihui Tang,Jiming Hu,Hua Zhang

Owing to the severe environmental and health issues posed by organophosphorus pesticides (OPs), a dual-enzyme cascade biosensing platform based on manganese dioxide (MnO2) and CRISPR/Cas12a was developed in this study. Smartphones were innovatively integrated with a stacked ensemble learning (SEL) model for ultrasensitive detection and dynamic monitoring of OPs in environmental water samples. A dual-enzyme cascade signal amplification strategy was used to construct this sensing platform. Acetylcholinesterase (AChE) catalyzes the generation of thiocholine (TCh), which, in turn, regulates the degradation of MnO2 nanosheets, releasing Cas12a activators and generating a fluorescence signal. Owing to the irreversible inhibition of AChE activity by OPs, dichlorvos (DDVP) was successfully detected, with a detection limit as low as 4.62 pg/mL. Additionally, the SEL model, integrated into the smartphone biosensing platform and incorporating random forest (RF), XGBoost, and ridge regression algorithms, exhibited strong performance in detecting OPs after optimization (R2 = 0.9985). In real water samples, the SEL model achieved a recovery rate of 93.1–103.1%, and the degradation kinetics of DDVP were successfully monitored over 24 h, revealing significant differences in DDVP degradation rates across various water matrices. This study is the first to report the integration of CRISPR/Cas12a biosensing technology with an SEL model-driven smartphone detection platform, providing a novel approach for sensitive, portable, and intelligent monitoring of OPs and offering new insights for water quality monitoring and early detection of environmental risks.

MRI/Fluorescence bimodal amplification system for cellular GSH detection and tumor cell imaging based on manganese dioxide nanosheet

Yuan Dandan,Ding Lairong,Sun Zhaomei,Li Xuemei

Here, we report a novel magnetic resonance imaging (MRI)/fluorescence bimodal amplification platform for the detection of glutathione (GSH) on the basis of redoxable manganese dioxide (MnO 2 ) nanosheets, which can be readily applied as a DNA nanocarrier, fluorescence quencher, and intracellular GSH-activated MRI contrast agent. The binding of aptamers that absorbed on the MnO 2 nanosheets to their target can facilitating the endocytosis of target-nanoprobes. Once endocytosed, the MnO 2 nanosheets can react with cellular GSH, resulting in the disintegration of nanosheets to generate plenty of Mn 2+ ions for MRI and releases the primers which were adsorbed on the MnO 2 nanosheets. Then the rolling circle amplification (RCA) reaction was initiated to amplify the fluorescence signal. In addition, after treatment with GSH, the MnO 2 nanosheets were reduced and then most of the fluorescence was recovered. Therefore, this MnO 2 nanoprobe exhibits excellent selectivity, suggesting a potential detection platform for analyzing the glutathione level in cells.

Relieving immunosuppression during long-term anti-angiogenesis therapy using photodynamic therapy and oxygen delivery

Qianyuan He,Zhanjie Zhang,Haojie Liu,Zhan Tuo,Jie Zhou,Yan Hu,Yajie Sun,Chao Wan,Zushun Xu,Jonathan F. Lovell,Desheng Hu,Kunyu Yang,Honglin Jin

Angiogenesis is an irreplaceable therapeutic cancer target, where anti-angiogenesis are drugs that are limited by their hydrophobicity and low therapeutic effects. What is more, the long-term shutdown of tumor blood vessel density also aggravates hypoxia and causes immunosuppression in the tumor microenvironment (TME). In order to solve these shortcomings, we developed a single therapeutic agent based on a bovine serum albumin nanocarrier that can co-deliver the anti-angiogenic drug Sorafenib (“S”) and the photosensitizer Ce6 (“C”) along with a molecular oxygen supply based on MnO2 (“M”) as a convenient one-pot formulated nanoscale agent (SCM@BSA). Compared with anti-angiogenesis monotherapy, SCM@BSA can not only improve upon the solubility and therapeutic effects of anti-angiogenesis agents, but it also reshapes the immunosuppressive TME during anti-angiogenic therapy. Together, these results point out that SCM@BSA synthesized via a very simple method can solve the shortcomings usually experienced during long-term anti-angiogenic therapy.

A novel smartphone-based CD-spectrometer for high sensitive and cost-effective colorimetric detection of ascorbic acid

Liubing Kong,Ying Gan,Tao Liang,Longjie Zhong,Yuxiang Pan,Dmitry Kirsanov,Andrey Legin,Hao Wan,Ping Wang

As a powerful tool for medical diagnosis and bioanalysis , conventional optical spectrometers are generally expensive, bulky and always require an accompanying data processing device. In this work, we developed a novel smartphone-based CD-spectrometer (SCDS) for high sensitive and ultra-portable colorimetric analysis , with the advantage of cost-effective and simplicity. The distance between the light source and slit, the structure of SCDS and the parameters of camera in the smartphone were all optimized to ensure the best analytical performance. Besides, the SCDS employed HSV color model and utilized the overall intensity calculated by summing V-value of adjacent position for the absorbance measurement. In this way the errors caused by the low resolution of CD-grating can effectively be eliminated to promote the sensitivity of the SCDS. The performance of the SCDS was first validated for colorimetric detection of BSA with a detection limit of 0.0073 mg/mL, which is superior compared to that of the microtiter plate reader (MTPR). Moreover, by combining with 3,3′,5,5′-tetramethylbenzidine-manganese dioxide (TMB-MnO 2 ) nanosheets reaction, a high sensitive and specific system for ascorbic acid detection was established. The SCDS gives a detection range from 0.6250 μM to 40 μM with a detection limit of 0.4946 μM for AA detection. Compared to other studies, the SCDS features wide detection range and very low detection limit with low cost instrument. Therefore, the SCDS will be an ideal and promising colorimetric system for point-of-care (POC) application in food security, disease diagnosis and environmental monitoring.

Decoupling electrolytes towards stable and high-energy rechargeable aqueous zinc–manganese dioxide batteries

Zhong Cheng,Liu Bin,Ding Jia,Liu Xiaorui,Zhong Yuwei,Li Yuan,Sun Changbin,Han Xiaopeng,Deng Yida,Zhao Naiqin,Hu Wenbin

Aqueous battery systems feature high safety, but they usually suffer from low voltage and low energy density, restricting their applications in large-scale storage. Here, we propose an electrolyte-decoupling strategy to maximize the full potential of Zn–MnO 2 batteries by simultaneously enabling the optimal redox chemistry of both the Zn and MnO 2 electrodes. The decoupled Zn–MnO 2 battery exhibits an open-circuit voltage of 2.83 V (in contrast to the typical voltage of 1.5 V in conventional Zn–MnO 2 batteries), as well as cyclability with only 2% capacity fading after deep cycling for 200 h. Benefiting from the full utilization of MnO 2 , the Zn–MnO 2 battery is also able to maintain approximately 100% of its capacity at various discharge current densities. We also demonstrate the feasibility of integrating the Zn–MnO 2 battery with a wind and photovoltaic hybrid power generating system. This electrolyte-decoupling strategy is shown to be applicable for other high-performance zinc-based aqueous batteries such as Zn–Cu and Zn–Ag batteries.

Lignosulfonate-Assisted Synthesis of Porous Carbon-Supported MnO2 Composites with Reinforced Interface Bonding for High-Performance Asymmetric Supercapacitors

Fangbao Fu,Xueqing Qiu,Dongjie Yang

Carbon/transition metal oxide composites exhibit promising potential as electrode materials for energy storage, but regulating their interfacial composite structures remains a formidable challenge. In this work, we develop a lignosulfonate-assisted synthesis strategy to fabricate a porous carbon-supported MnO2 composite (LSC/MnO2-2) with a robust interface for asymmetric supercapacitors (ASCs). The functionalized lignin porous carbon, achieved through π–π interactions with lignosulfonate, exhibited improved dispersibility, thereby facilitating the deposition of MnO2 onto the carbon matrix. Consequently, LSC/MnO2-2 demonstrates uniform MnO2 loading and enhanced interfacial bonding. The robust interaction between Mn sites and the lignosulfonate-functionalized carbon substrate can promote electron transfer and ion transfer kinetics, effectively activating the electrochemical activity of MnO2. The as-prepared LSC/MnO2-2 demonstrates high specific capacitances of 750 F/g at 0.5 A/g and 400 F/g at 10.0 A/g in a 1 M KOH electrolyte. Furthermore, the assembled ASC exhibits an outstanding energy density of 54.4 Wh/kg at 998.2 W/kg and excellent cyclic stability (94.7% retention over 10,000 cycles at 2.0 A/g). This study presents an alternative method to precisely control the deposition of metal oxides onto carbon materials, aiming to enhance the performance of carbon composites.

Interfacial synergy in setaria viridi-like Mn2O3@MnO2 heterojunctions with switchable nanotube/nanosheet morphologies for HCHO catalytic oxidation

Suhong Lu,Shuo Wang,Chengyu Xu,Yewei Chen,Nan Sun,Jurong Liu,Yuzhen Fang,Guilong Liu

A series of setaria viridis-like Mn 2 O 3 @MnO 2 - T ( T = 3, 6, 9, 12 and 15 h) heterojunctions with switchable nanotube/nanosheet morphologies were synthesized via a controllable redox process. This involved precisely regulating the duration of acidic KMnO 4 treatment to induce in situ MnO 2 growth on rod-like Mn 2 O 3 substrates. Among these, Mn 2 O 3 @MnO 2 -12 exhibited the highest catalytic activity and outstanding stability, achieving 100 % conversion of 150 ppm HCHO at 50 °C under conditions of 30 % relative humidity and 36,000 mL g cat −1 h −1 . The strong electronic coupling at the interface between the Mn 2 O 3 (211) and MnO 2 (110) planes lowered the energy barrier for HCHO oxidation. Lattice mismatch at this interface likely induced oxygen vacancies, critical for activating O 2 into reactive oxygen species. Correspondingly, abundant surface active oxygen was observed in Mn 2 O 3 @MnO 2 -12, which contributed to the formation of dioxymethylene and formate intermediates, as monitored by in situ DRIFTS. Furthermore, greater charge enrichment on Mn combined with a lower work function ( W f ) indicated enhanced electron transfer to reactants and intermediates, establishing a favorable catalytic environment. This study provides a viable strategy for designing cost-effective, highly efficient transition metal oxide catalysts suitable for low-temperature HCHO oxidation.

Ag-modulated mesoporous δ-MnO2 cathodes mitigate pseudo-capacitance and enhance specific capacity of aqueous zinc ion batteries

Boyou Hu,Haiyang Li,Menglei Wang,Zhiqiang Rao,Liqing Hao,Xuan Yu,Meng Zhang

The development of high-performance aqueous zinc-ion batteries (AZIBs) is promising for energy storage applications, yet challenges persist due to excessive pseudo-capacitance, structural instability and low conductivity of cathode materials. In this study, an Ag-doped mesoporous δ-MnO 2 nanocomposite (Ag–MnO 2 ) was rationally designed as a high-specific-capacity cathode material for AZIBs. Intercalated Ag + stabilize the layered δ-MnO 2 framework and expand ion diffusion channels, while surface-anchored Ag nanoparticles enhance electrical conductivity, optimize pseudo-capacitance and enhance reaction kinetics of δ-MnO 2 . Electrochemical tests reveal that Ag–MnO 2 delivers an amazing specific capacity of 491.7 mAh g −1 , a high power density of 133.1 W kg −1 and a superb energy density of 660.0 Wh kg −1 at 0.1 A g −1 , significantly outperforming pristine δ-MnO 2 , an approximate power density of 135.6 W kg −1 and a poor energy density of 457.1 Wh kg −1 at 0.1 A g −1 . Furthermore, Ag–MnO 2 exhibits exceptional cycling stability, retaining 95.6 % capacity after 800 cycles at 1.0 A g −1 . Ex-situ X-ray diffraction and X-ray photoelectron spectroscopy analyses elucidate the energy storage mechanism of Ag–MnO 2 in AZIBs. A flexible pouch cell fabricated with Ag–MnO 2 demonstrates stable operation under bending conditions, which holds enormous potential in flexible battery applications, achieving high electrochemical performance of 470.3 mAh g −1 , 112.2 W kg −1 and 610.7 Wh kg −1 at 0.1 A g −1 . This work provides a scalable strategy for designing high-performance AZIBs cathodes and offers insights into material regulation for overcoming energy storage limitations, applicable to broader energy storage systems.

MnO2/TiO2 Nanotube Array-Coated Titanium Substrates as Anodes for Electrocatalytic Oxidation of As(III) in Aqueous Solution

Yuanjie Xiong,Xiang Liu,Tian Cheng Zhang,Shaojun Yuan

The conversion of As(III) to As(V) in groundwater is an urgent issue, owing to the higher mobility, stronger toxicity, and weaker binding ability of As(III). In this work, the electrocatalytic oxidation of As(III) was efficiently achieved with a facile and environmentally benign method by using hierarchical MnO2-deposited TiO2 nanotube arrays (MnO2/TNAs) as the anode. The electrocatalytic oxidation performance of the as-fabricated MnO2/TNA-coated anode was systematically investigated. The results exhibited that such as-fabricated MnO2/TNAs had a high oxidation efficiency of 90% at a low concentration of As(III) (1 mg L–1). Furthermore, the reaction mechanism was systematically studied by electron spin resonance and free radical capture experiments. The oxidation of As(III) was accomplished via both direct oxidation on the anode surface and indirect oxidation of the reactive oxygen species. The highly efficient TNA-based anode offers a potentially promising advanced material for electrochemical oxidation of trace As(III) in the practical field.

The combination of MnO2@Lipo-coated gefitinib and bevacizumab inhibits the development of non-small cell lung cancer

Jisong Zhang,Li Xu,Huihui Hu,Enguo Chen