Functionalized MoS2 Nanosheets Research Articles

Ultra-thin PTMSP nanocomposite membranes incorporated with functionalized MoS2 nanosheets for pharmaceutical concentration and solvent recovery

Organic solvent nanofiltration (OSN) membranes with enhanced separation performance and excellent structure stability are of great benefit in recovering organic solvent and concentrating molecules in pharmaceutical industry. In this study, we developed a smooth and ultra-thin nanocomposite membrane by incorporating sodium dodecylbenzene sulfonate (SDBS) functionalized molybdenum sulfide (MoS2) nanosheets into an ultra-thin poly-trimethylsilylpropyne (PTMSP) skin layer on polysulfone (PSf) substrate via a facile solution coating method. The two-dimensional (2D) SDBS-MoS2 with improved compatibility was employed to provide selective channels for solvent permeation while reducing defect cavities to increase solute rejection. The resulting membrane exhibited a significantly improved methanol permeance of up to 8.38 L m−2 h−1 bar−1, signifying a noteworthy 56 % increment compared to the pristine membrane. Additionally, the RB rejection increased from 95.05 % to 97.72 %. The as-prepared membrane also demonstrated favorable long-term stability and efficient molecules separation capabilities in the pharmaceutical industry. This work demonstrated that the compatibility and dispersibility of 2D MoS2 could be improved by adding SDBS, resulting in a SDBS-MoS2-PTMSP membrane with excellent OSN performance and outstanding long-term stability, making it highly promising for industrial applications.

MoS2 nanosheets based label-free colorimetric aptasensor for Escherichia coli O157: H7 detection

The aggregation behavior of large-scale two-dimensional molybdenum disulfide (MoS2) nanosheets prepared by sonication-assisted exfoliation in environmental friendly 45% ethanol/water mixture under different conditions (e.g., salt concentration, cation valence and nanosheets size) had been examined to make them more appropriate for biological sensing application. Adjustment of sonication time and centrifuging speed could be utilized to select MoS2 nanosheets with various concentrations and sizes. Higher concentrations of salt and cations with higher valence were more effective to aggregate MoS2 nanosheets and settle them than their counterparts, which could be attributed to the perturbation of attractive van der Waals forces and repulsive Coulombic interactions. Moreover, the ethanol in mixture was capable of assisting MoS2 nanosheets to resist this aggregation initiated by salt but it would disturb the stability of aptamer functionalized MoS2 nanosheets in salt solution. The interplay of Escherichia coli O157: H7 (E. coli O157:H7) aptamer functionalized MoS2 nanosheets and salt was then inspired to develop a high sensitive detection method of E. coli O157:H7. The introduction of target bacteria induced MoS2 nanosheets to be exposed to cations, and promoted the aggregation and sedimentation behavior of MoS2 nanosheets. The change in extinction of MoS2 nanosheets had a linear relationship with E. coli O157:H7 concentration in a range of 500–5000 CFU/mL with a detection limit of 116 CFU/mL. This proposed colorimetric sensor expands the application scope of MoS2 nanosheets and shows its promising potential as an alternative tool for bacteria detection in food and water quality monitoring.

Construction of CpG Delivery Nanoplatforms by Functionalized MoS2 Nanosheets for Boosting Antitumor Immunity in Head and Neck Squamous Cell Carcinoma.

Despite the promising achievements of immune checkpoint blockade (ICB) therapy for tumor treatment, its therapeutic effect against solid tumors is limited due to the suppressed tumor immune microenvironment (TIME). Herein, a series of polyethyleneimine (Mw = 0.8k, PEI0.8k )-covered MoS2 nanosheets with different sizes and charge densities are synthesized, and the CpG, a toll-like receptor-9 agonist, is enveloped to construct nanoplatforms for the treatment of head and neck squamous cell carcinoma (HNSCC). It is proved that functionalized nanosheets with medium size display similar CpG loading capacity regardless of low or high PEI0.8k coverage owing to the flexibility and crimpability of 2D backbone. CpG-loaded nanosheets with medium size and low charge density (CpG@MM -PL ) could promote the maturation, antigen-presenting capacity, and proinflammatory cytokines generation of bone marrow-derived dendritic cells (DCs). Further analysis reveals that CpG@MM -PL effectively boosts the TIME of HNSCC in vivo including DC maturation and cytotoxic T lymphocyte infiltration. Most importantly, the combination of CpG@MM -PL and ICB agents anti-programmed death 1 hugely improves the tumor therapeutic effect, inspiring more attempts for cancer immunotherapy. In addition, this work uncovers a pivotal feature of the 2D sheet-like materials in nanomedicine development, which should be considered for the design of future nanosheet-based therapeutic nanoplatforms.

A graphitic nano-onion/molybdenum disulfide nanosheet composite as a platform for HPV-associated cancer-detecting DNA biosensors

An electrochemical DNA sensor that can detect human papillomavirus (HPV)-16 and HPV-18 for the early diagnosis of cervical cancer was developed by using a graphitic nano-onion/molybdenum disulfide (MoS2) nanosheet composite. The electrode surface for probing DNA chemisorption was prepared via chemical conjugation between acyl bonds on the surfaces of functionalized nanoonions and the amine groups on functionalized MoS2 nanosheets. The cyclic voltammetry profile of an 1:1 nanoonion/MoS2 nanosheet composite electrode had an improved rectangular shape compared to that of an MoS2 nanosheet elecrode, thereby indicating the amorphous nature of the nano-onions with sp2 distancing curved carbon layers that provide enhanced electronic conductivity, compared to MoS2 nanosheet only. The nanoonion/MoS2 sensor for the DNA detection of HPV-16 and HPV-18, respectively, was measured at high sensitivity through differential pulse voltammetry (DPV) in the presence of methylene blue (MB) as a redox indicator. The DPV current peak was lowered after probe DNA chemisorption and target DNA hybridization because the hybridized DNA induced less effective MB electrostatic intercalation due to it being double-stranded, resulting in a lower oxidation peak. The nanoonion/MoS2 nanosheet composite electrodes attained higher current peaks than the MoS2 nanosheet electrode, thereby indicating a greater change in the differential peak probably because the nanoonions enhanced conductive electron transfer. Notably, both of the target DNAs produced from HPV-18 and HPV-16 Siha and Hela cancer cell lines were effectively detected with high specificity. The conductivity of MoS2 improved by complexation with nano-onions provides a suitable platform for electrochemical biosensors for the early diagnosis of many ailments in humans.Graphical

Interface Engineering of 2D NiMOF–MoS2 Hybrids for Electrocatalytic Hydrogen Evolution

Interface engineering of heterostructures with defined characteristics is crucial to unravel their potential by ensuring the synergism in both structural and interface effects. This work unveils the potential of interface-engineered directly linked NiMOF–MoS2 hybrids for electrocatalytic hydrogen evolution and electrochemical supercapacitor applications. Directly linked NiMOF with covalently functionalized defect-rich MoS2 nanosheets (by aminophenyl linkages) maintained their large surface area with active sites for adsorption of hydrogen atoms (Hads) during electrocatalysis, where the direct interconnection ensures the charge transfer to active sites across the interface. Owing to the synergistic effect of both morphology and electron distribution across the interface, the hybrids exhibited the highest hydrogen production with an onset overpotential of 469 mV (Tafel slope of 152 mV dec–1) and excellent specific capacitance (3807 F g–1) as compared with the sole functionalized MoS2 nanosheets.

Rationally designed rare-earth elements functionalized MoS2 nanosheets towards reducing fire hazards of epoxy resin

As well-known, rare-earth elements had potentials for enhancing the flame retardancy of polymer materials. Herein, a novel 0D/2D structure of cerium stannate (Ce2Sn2O7) hybridized with molybdenum disulfides (CSO@MoS2) was synthesized...

High performance internally pressurized hollow fiber thin-film nanocomposite nanofiltration membrane incorporated with tannic acid functionalized MoS2 nanosheets for wastewater treatment

An internally pressurized hollow fiber thin film nanocomposite (TFN) nanofiltration (NF) membrane with tannic acid (TA) functionalized two dimensional MoS2 (TA-MoS2) nanosheets incorporated in its polyamide layer was fabricated via interfacial polymerization process. The extra-low amount TA-MoS2 nanosheets could effectively regulate the interfacial polymerization process to foster the formation of an ultra-smooth and defect-free separation layer on the internal surface of hollow fiber substrate. In this way, we provided additional transport channel in the separation layer for fast water transmission, and achieved the high selectivity in the separation of dye, sulfate and heavy metal salt. The optimized hollow fiber TFN NF membrane possesses a water permeance of 143 L m−2 h−1 MPa−1. Meanwhile, it has a dye rejection of 97 % for most dyes tested and a Cl− / SO42− selectivity of 67. In addition, its rejection of CuSO4, ZnSO4 and MnSO4 is higher than 90 %. Moreover, it also shows better alkali resistance and chlorine resistance performance. Thus, it shows a broad application prospect in dye, sulfate and heavy metal salts removal from industrial wastewater.

Porphyrin covalently functionalized MoS2 nanosheets: “Click” synthesis and tunable nonlinear absorption

Functionalized MoS2 nanosheets are of significant academic and commercial interest due to their use in electronic and photonic applications as transistors, electrocatalysts, electrodes, and nonlinear optical materials. However, MoS2 nanosheets exhibit low reactivity and poor dispersibility in common solvents, which significantly hinders their functionalization with optoelectronic groups and their downstream applications. Herein, a porphyrin covalently functionalized MoS2 nanohybrid (MoS2-Por) is synthesized by a mild thiol−ene “click” reaction. Optical studies demonstrate that a dispersion of the MoS2-Por nanohybrid in N,N-dimethylformamide (DMF) exhibits reverse saturable absorption (RSA) behavior to femtosecond pulsed laser irradiation at 800 nm, in contrast to the saturable absorption (SA) displayed by MoS2 nanosheets. This significant switch likely stems from enhanced two-photon absorption (TPA) in the MoS2 nanosheets, which may be ascribed to efficient charge transfer in the excited-state of the MoS2-Por nanohybrid. Polymethyl methacrylate (PMMA) films MoS2-Por/PMMA exhibit a low optical limiting threshold of 1.2 mJ cm-2 (18.3 GW cm-2), indicating great potential as an optical limiter. The MoS2-Por nanohybrid also exhibits stronger self-focusing than MoS2 nanosheets towards femtosecond pulses at 800 nm due to the increased free-carries concentration arising from the improved TPA. These observations demonstrate that the MoS2-Por nanohybrid is an excellent candidate for optical limiting in the infrared region towards femtosecond pulses, and shed new light on the construction of covalently functionalized MoS2 nanohybrids for tuning nonlinear optical properties and broadening application scope.

Nanoscale Control of DNA-Linked MoS2-Quantum Dot Heterostructures.

The ability to control the assembly of mixed-dimensional heterostructures with nanoscale control is key for the fabrication of novel nanohybrid systems with new functionalities, particularly for optoelectronics applications. Herein we report a strategy to control the assembly of heterostructures and tune their electronic coupling employing DNA as a linker. We functionalized MoS2 nanosheets (NSs) with biotin-terminated dsDNA employing three different chemical strategies, namely, thiol, maleimide, and aryl diazonium. This allowed us to then tether streptavidinated quantum dots (QDs) to the DNA functionalized MoS2 surface via biotin-avidin recognition. Nanoscale control over the separation between QDs and NSs was achieved by varying the number of base pairs (bp) constituting the DNA linker, between 10, 20, and 30 bp, corresponding to separations of 3.4, 6.8, and 13.6 nm, respectively. Spectroscopic data confirmed the successful functionalization, while atomic force and transmission electron microscopy were employed to image the nanohybrids. In solution steady-state and time-resolved photoluminescence demonstrated the electronic coupling between the two nanostructures, that in turn was observed to progressively scale as a function of DNA linker employed and hence distance between the two nanomoieties in the hybrids.

Functionalized MoS2 nanosheets enabled nanofiltration membrane with enhanced permeance and fouling resistance

In this study, a novel thin film nanocomposite (TFN) membrane incorporated with -OH functionalized molybdenum disulfide (OH-MoS 2 ) nanosheets was fabricated through interfacial polymerization between piperazine (PIP) and trimesoyl chloride (TMC) by addition of nanosheets in the aqueous phase. The physicochemical characterizations of the resultant TFN membrane confirmed the embedding of OH-MoS 2 nanosheets and showed excellent compatibility with polypiperazine amide (PPA) matrix, as well as the nanosheets incorporation significantly increased the hydrophilicity, negative charge, surface roughness. In addition, the hydroxyl groups attached to the MoS 2 nanosheets can be covalently bonded into the skin layer through its reaction with TMC, promoting excellent compatibility with the polymer matrix. At an optimum concentration of 0.010 wt% OH-MoS 2 , the TFN membrane exhibited 45.17% increase in pure water flux (84.14 L m −2 h −1 ) when compared to control membrane (57.96 L m −2 h −1 ) and maintained stable salt rejection for Na 2 SO 4 (96.67%). This optimized TFN membrane exhibited high normalized flux of 96.92% when compared to 91.22% for control membrane and high flux recovery ratio of 98.88% was maintained as well as enhanced organic removal at 89.14% in terms of dissolved organic carbon (DOC) and 99.2% as ultraviolet absorbance at 254 nm (UV 254 ) was recorded during 6 h filtration studies with humic acid containing feed water. 0.010 wt% OH-MoS 2 incorporated membranes exhibited enhanced permeance, salt rejection and stability along with excellent fouling resistance and organic removal demonstrating the potential of OH-MoS 2 nanosheets for engineering high performance and fouling resistant TFN NF membranes for water treatment. • TFN NF membrane by embedding OH-MoS 2 nanosheet into PPA layer via IP reaction. • OH-MoS 2 with abundant oxygen, sulphur groups improved hydrophilicity of membrane. • 0.01 wt% OH-MoS 2 membrane showed 45.17% higher flux and 96.67% Na 2 SO 4 rejection. • TFN membrane shows 96.92% normalized flux compared to 91.22% for control membrane. • Excellent organic removal and stability was exhibited by TFN membrane.

Covalent treatment of carbon fibre with functionalized MoS2 nanosheets using thiol-ene click chemistry: The improvement of interface in multiscale epoxy composites

The multiscaling method is contemplated as an effective approach for improving the interfacial adhesion in carbon fibre composites. Nonetheless, the lack of interactions between the nanomaterials and the other constitutes including fibre and matrix resulted in the deterioration of mechanical performance in composites. Herein, the combination of a scalable synthesis method based on ball milling and thiol-ene click chemistry has been utilized to graft the functionalized MoS 2 nanosheets with large lateral dimensions (∼537 nm) on the carbon fibres surface for the first time. The proposed method did not significantly affect the mechanical properties of the carbon fibre, leading to augmentation in the performance of composites by the virtue of higher surface energy and roughness of the fibre surface. In other words, the obtained results have demonstrated that the presence of activated MoS 2 nanosheets on the carbon fibre surface possesses the ability to promote interfacial adhesion and interlaminar shear strength by 74% and 36% respectively, compared to the pristine unsized carbon fibre. Additionally, the effectiveness and the efficacy of MoS 2 -CF reinforcements can be delineated by the enhancements of flexural strength and modulus of multiscale composites by 49.5% and 33.6%, respectively. The morphology of both fibres and fractured surfaces of composites indicated that the random distribution of nanosheets on the fibre surface facilitates the energy dissipation via breakage, pullout, and bridging mechanisms which subsequently improved the overall performance of the developed composites.

Lignosulfonate functionalized nanomaterials for enhancement of the electrochemical performance of polyaniline

The electrochemical enhancement of polyaniline (PANI) by adding nanomaterials is closely related with the dispersion state of the nanomaterials in PANI. Herein, we demonstrate the fabrication of well-mixed PANI/nanomaterials composites through solid-phase exfoliation and subsequent in-situ polymerization. Bulk molybdenum disulfide (MoS2) or carbon nanotube (CNT) bundles were firstly ball-milled in the presence of calcium lignosulphonate to provide lignosulfonate (LS) noncovalently functionalized MoS2 nanosheets or CNTs, which were then used as skeletons for in-situ polymerization of aniline. The resulted nanocomposites exhibited enhanced electrochemical properties as compared with pure PANI. Typically, the ternary composite PANI/MoS2-LS/CNT-LS delivered a specific capacitance of 458.9 F/g, a 63% improvement than PANI at 1 A/g in a three-electrode system. Furthermore, excellent cycle stability (86% capacitance retention after 10, 000 charge-discharge cycles) and high specific energy (10.9 Wh/kg at specific power of 265.3 W/kg) were obtained in a coin-type symmetric supercapacitor. The study provides an efficient and facile approach for fabrication of conductive polymer/nanomaterials composite for supercapacitors with good stability and performance.

Ultra-smooth and ultra-thin polyamide thin film nanocomposite membranes incorporated with functionalized MoS2 nanosheets for high performance organic solvent nanofiltration

Organic solvent nanofiltration (OSN) membranes are the key factors for the treatment of organic solution via OSN technology. In this work, we fabricated a kind of ultra-thin and ultra-smooth thin-film nanocomposite (TFN) OSN membrane using interfacial polymerization (IP) process with ultra-low concentration for both the aqueous and the organic monomers, together with doped tannic acid (TA) functionalized Molybdenum disulfide (MoS2) nanosheets of ultra-low content in the aqueous monomer solution, and followed by post-IP chemical crosslinking and solvent activation procedures. The results demonstrated that the incorporated TA-MoS2 nanosheets not only help to promote the solvent permeation, but also help to increase the solvent resistance and fouling resistance of the fabricated membrane. The optimal TFN OSN membrane fabricated using 0.05 wt% aqueous m-phenylenediamine (MPD) solution doped with TA-MoS2 nanosheets content of 50 mg L−1 and 0.0025 wt% trimesoyl chloride (TMC) / n-hexane solution has an ultra-thin barrier layer, with an average thickness of about 15 nm. This endows it a much higher pure DMF permeance of 219.1 L m−2 h−1 MPa−1, which is much superior over most of literature works. Meanwhile, the fabricated TFN OSN membrane achieves a rejection of 99.1 % for rhodamine B (RDB, 479 Dalton), which is about 10.1 % increment compared with that of the baseline thin-film composite (TFC) membrane. The TFN OSN membrane also features an ultra-smooth skin layer, with a surface roughness of merely about 2.0 nm, which is quite beneficial for its fouling resistance performance. Moreover, the TFN OSN membrane features outstanding high solvent resistance. It remained a nearly constant and extremely high rejection for Rose Begal (RB, 1017 Dalton), about 99.9 %, and a much higher DMF permeance, 101 ± 2 L m−2 h−1 MPa−1, after cross-flow filtration for more than 200 h using 100 mg L−1 RB / DMF solution as feed, which is seldomly reported in literature. Even being immersed in DMF at 80 °C for more than 144 h, it remained a rejection of higher than 98 % for Rhodamine B (479 Dalton), indicating its superior solvent resistance and promising industrial application prospect.

High Performance Internally Pressurized Hollow Fiber Thin-Film Nanocomposite Nanofiltration Membrane Incorporated with Tannic Acid Functionalized Mos2 Nanosheets for Wastewater Treatment

High Performance Internally Pressurized Hollow Fiber Thin-Film Nanocomposite Nanofiltration Membrane Incorporated with Tannic Acid Functionalized Mos2 Nanosheets for Wastewater Treatment

Co-Delivery of Doxorubicin and Chloroquine by Polyglycerol Functionalized MoS2 Nanosheets for Efficient Multidrug-Resistant Cancer Therapy.

2D MoS2 has shown a great potential in biomedical applications, due to its superior loading capacity, photothermal property, and biodegradation. In this work, polyglycerol functionalized MoS2 nanosheets with photothermal and pH dual-stimuli responsive properties are used for the co-delivery of doxorubicin and chloroquine and treatment of multidrug-resistant HeLa (HeLa-R) cells. The polyglycerol functionalized MoS2 nanosheets with 80nm average size show a high biocompatibility and loading efficiency (≈90%) for both drugs. The release of drugs from the nanosheets at pH 5.5 is significantly promoted by laser irradiation leading to efficient destruction of incubated HeLa-R cells. In vitro evaluation shows that the designed nanoplatform has a high ability to kill HeLa-R cells. Confocal experiments demonstrate that the synthesized drug delivery system enhances the cellular uptake of DOX via folic acid targeting ligand. Taking advantage of the combined properties including biocompatibility and targeting ability as well as high loading capacity and photothermal release, this multifunctional nanosystem is a promising candidate for anticancer therapy.

Gamma-ray initiated polymerization from polydopamine-modified MoS2 nanosheets with poly (ionic liquid) and their utilization for adsorptive organic dyes with enhanced efficiency

In this paper, we report the fabrication of ionic liquid (IL)-modified molybdenum disulfide (MoS2) composites via a simple but effective method, that relied on Gamma-ray-initiated polymerization of polydopamine (PDA) modified MoS2 nanosheets using IL as a monomer. The adsorptive removal of Congo red (CR) from aqueous medium by MoS2@PDA@IL composites was investigated. Batch experiments were carried out thoroughly to explore the effects of various experimental factors, such as contact time, containment initial concentration, and the function of pH and system temperature on the adsorption of MoS2@PDA@IL composites towards CR. Based on the experimental data, the adsorption kinetics, isotherms (Langmuir and Freundlich) and thermodynamics were also studied. We demonstrated that the adsorption of CR on MoS2@PDA@IL is a spontaneous and endothermic process. The amount of adsorbed CR of the MoS2@PDA@IL composites (Qe, max = 112.16 mg/g) is 2.77 times that of pristine MoS2 (Qe, max = 40.54 mg/g). The above results demonstrated that PIL functionalized MoS2 nanosheets are promising for adsorptive removal of environmental pollutants. More importantly, owing to the universal adhesion capability of polydopamine, the method might also be extended for the fabrication of other polymeric composites with different functions for various applications. Therefore, this work will attract interest from scientists in the materials, chemistry and environmental fields.

Ammonia Generation from 2D MoS2 Catalysts

We use metallic MoS2 as a catalyst for N2 fixation and NH3 generation. Based on the current literature with regard to MoS2 catalytic performance for NH3 generation, it is tracking with catalytic performance for hydrogen evolution. For example, if you increase edge sites with 2D MoS2 structuring or incorporate more vacancies/defect sites, the hydrogen evolution reaction improves. The same is true of NH3 formation. If we take this one step further, hydrogen generation further increases if MoS2 is converted to its thermodynamically unstable metallic state and is stabilized in this state with functional groups. Therefore, we extend this correlation to NH3 generation. We expect that the N2 fixation and NH3 generation will improve and be stable if we use metallic, functionalized MoS2 nanosheets. This hypothesis is tested and reported. We will also comment on the selectivity for the H2 versus NH3 generation from this catalyst with various functional groups.

Machine Learning-Assisted Array-Based Detection of Proteins in Serum Using Functionalized MoS2 Nanosheets and Green Fluorescent Protein Conjugates.

Abnormal concentrations of a specific protein or the presence of some biomarker proteins may indicate life-threatening diseases. Pattern-based detection of specific analytes using affinity-regulated receptors is one of the potential alternatives to specific antigen–antibody-based detection. In this report, we have schemed a sensor array by using various functionalized two-dimensional (2D)-MoS2 nanosheets and green fluorescent protein (GFP) as the receptor and the signal transducer, respectively. Two-dimensional MoS2 has been used as a promising candidate for recognition of the bioanalytes because of its high surface-to-volume ratio compared to those of other nanomaterials. Easy surface tunability of this material provides additional advantages to analyze the target of interest. The optimized 2D-MoS2–GFP conjugates are able to discriminate 15 different proteins at 50 nM concentration with a detection limit of 1 nM. Moreover, proteins in the binary mixture and in the presence of serum were discriminated successfully. Ten different proteins in serum media at relevant concentrations were classified successfully with 100% jackknifed classification accuracy, which proves the potentiality of the above system. We have also implemented and discussed the implication of using different machine learning models on the pattern recognition problem associated with array-based sensing.

Droplet Microarray Based on Nanosensing Probe Patterns for Simultaneous Detection of Multiple HIV Retroviral Nucleic Acids.

Multiplexed detection of viral nucleic acids is important for rapid screening of viral infection. In this study, we present a molybdenum disulfide (MoS2) nanosheet-modified dendrimer droplet microarray (DMA) for rapid and sensitive detection of retroviral nucleic acids of human immunodeficiency virus-1 (HIV-1) and human immunodeficiency virus-2 (HIV-2) simultaneously. The DMA platform was fabricated by omniphobic–omniphilic patterning on a surface-grafted dendrimer substrate. Functionalized MoS2 nanosheets modified with fluorescent dye-labeled oligomer probes were prepatterned on positively charged amino-modified omniphilic spots to form a fluorescence resonance energy transfer (FRET) sensing microarray. With the formation of separated microdroplets of sample on the hydrophobic–hydrophilic micropattern, prepatterned oligomer probes specifically hybridized with the target HIV genes and detached from the MoS2 nanosheet surface due to weakening of the adsorption force, leading to fluorescence signal recovery. As a proof of concept, we used this microarray with a small sample size (<150 nL) for simultaneous detection of HIV-1 and HIV-2 nucleic acids with a limit of detection (LOD) of 50 pM. The multiplex detection capability was further demonstrated for simultaneous detection of five viral genes (HIV-1, HIV-2, ORFlab, and N genes of SARS-COV-2 and M gene of Influenza A). This work demonstrated the potential of this novel MoS2-DMA FRET sensing platform for high-throughput multiplexed viral nucleic acid screening.

Magnetic MoS2 nanosheets as recyclable solar-absorbers for high-performance solar steam generation

To deal with water scarcity, solar steam generation has been widely regarded as one of the promising methods for freshwater production. In this work, for the first time, a novel recyclable MoS2-based nanocomposite (magnetic MoS2 nanosheets) was fabricated via the in-situ growth of nano Fe3O4 on the polydopamine (PDA)-functionalized MoS2 nanosheets, and subsequently applied as the solar absorber in the volumetric evaporation systems to generate solar steam. The magnetic MoS2 nanosheets showed a superhigh solar absorption of over 96% within the whole wavelength range of 200–2500 nm. As a result, a high evaporation efficiency of 79.2% under the low illumination of 2.5 kW m−2 was achieved. In addition, the magnetic MoS2 nanosheets not only showed the long-term well dispersion in aqueous solution due to the introduction of hydrophilic PDA, but also exhibited a fast and effective separation from aqueous solution with the help of the decorating nano Fe3O4, which much benefited to the continuously efficient solar steam generation and its good recyclability, respectively. Therefore, the MoS2-based nanomaterials in this work showed good prospects for solar energy harvesting.