Asymmetric Nanoparticles Research Articles

Synthesis of early transition metal oxide nanomaterials and their conversion to nitrides

The synthesis of nanorods and nanowires of early transition metal oxides by hydrothermal methods and the conversion of some bulk oxides to nitrides in NH3 flow are both well established. However, the conversion of such oxide nanostructures to nitrides is not as well explored but could be a valuable method of producing nanowires, nanorods, and other asymmetric or high aspect ratio nanoparticles of the highly conductive metal nitrides. In this work, nanostructures of TiO2, V2O5, MoO3, and WO3 and mixtures thereof were synthesized by hydrothermal reactions, and conversion into nitride was attempted by heating the oxide material under NH3 flow with or without N2 flow. It was found that slow heating produces the best shape retention, but the nitridized products are porous in even the most favorable cases. The products were characterized by X-ray powder diffraction and scanning electron microscopy. Two-point conductivity measurements were done on the nitride materials, and optical measurements to characterize the plasmon absorption were done in favorable cases.

Asymmetric modification of cellulose nanocrystals with PAMAM dendrimers for the preparation of pH-responsive hairy surfaces

In this work, we present a straightforward method to attach a globular dendrimer at the reducing end of cellulose nanocrystals obtained from tunicates (t-CNC). We investigated the first four generations of poly(amidoamine) dendrimers (PAMAMs G0 to G3) to obtain hybrid t-CNCs. The aggregation behavior of hybrid t-CNCs was studied by dynamic light scattering (DLS) and scanning transmission electron microscopy (STEM); and interactions of these asymmetric nanoparticles with gold surface were elucidated using quartz crystal microbalance with dissipation (QCM-D) and surface plasmon resonance (SPR). Hybrid t-CNCs formed hairy layers onto gold surface combining the properties of rigid rod-like nanocrystals with globular and flexible PAMAM dendrimers. Moreover, the presence of amino groups provided pH-responsive properties to hybrid t-CNCs, and QCM-D results revealed reversible swelling/deswelling behavior. Thereby, we achieved to synthesize tree-shaped functional bio-based materials that adsorbed on gold and formed pH-responsive hairy surfaces.

Effect of Zinc Oxide Nano-Additives and Soybean Biodiesel at Varying Loads and Compression Ratios on VCR Diesel Engine Characteristics

The present investigation is directed towards synthesis of zinc oxide (ZnO) nanoparticles and steady blending with soybean biodiesel (SBME25) to improve the fuel properties of SBME25 and enhance the overall characteristics of a variable compression ratio diesel engine. The soybean biodiesel (SBME) was prepared using the transesterification reaction. Numerous characterization tests were carried out to ascertain the shape and size of zinc oxide nanoparticles. The synthesized asymmetric ZnO nanoparticles were dispersed in SBME25 at three dosage levels (25, 50, and 75 ppm) with sodium dodecyl benzene sulphonate (SDBS) surfactant using the ultrasonication process. The quantified physicochemical properties of all the fuels blends were in symmetry with the American society for testing and materials (ASTM) standards. Nanofuel blends demonstrated enhanced fuel properties compared with SBME25. The engine was operated at two different compression ratios (18.5 and 21.5) and a comparison was made, and best fuel blend and compression ratio (CR) were selected. Fuel blend SBME25ZnO50 and compression ratio (CR) of 21.5 illustrated an overall enhancement in engine characteristics. For SBME25ZnO50 and CR 21.5 fuel blend, brake thermal efficiency (BTE) increased by 23.2%, brake specific fuel consumption (BSFC) were reduced by 26.66%, and hydrocarbon (HC), CO, smoke, and CO2 emissions were reduced by 32.234%, 28.21% 22.55% and 21.66%, respectively; in addition, the heat release rate (HRR) and mean gas temperature (MGT) improved, and ignition delay (ID) was reduced. In contrast, the NOx emissions increased for all the nanofuel blends due to greater supply of oxygen and increase in the temperature of the combustion chamber. At a CR of 18.5, a similar trend was observed, while the values of engine characteristics were lower compared with CR of 21.5. The properties of nanofuel blend SBME25ZnO50 were in symmetry and comparable to the diesel fuel.

Effect of Nano-Graphene Oxide and n-Butanol Fuel Additives Blended with Diesel—Nigella sativa Biodiesel Fuel Emulsion on Diesel Engine Characteristics

The present investigation uses a blend of Nigella sativa biodiesel, diesel, n-butanol, and graphene oxide nanoparticles to enhance the performance, combustion and symmetric characteristics and to reduce the emissions from the diesel engine of a modified common rail direct injection (CRDI). A symmetric toroidal-type combustion chamber and a six-hole solenoid fuel injector were used in the current investigation. The research aimed to study the effect of two fuel additives, n-butanol and synthesized asymmetric graphene oxide nanoparticles, in improving the fuel properties of Nigella sativa biodiesel (NSME25). The concentration of n-butanol (10%) was kept constant, and asymmetric graphene oxide nano-additive and sodium dodecyl benzene sulphonate (SDBS) surfactant were added to n-butanol and NSME25 in the form of nanofluid in varying proportions. The nanofluids were prepared using a probe sonication process to prevent nanoparticles from agglomerating in the base fluid. The process was repeated for biodiesel, n-butanol and nanofluid, and four different stable and symmetric nanofuel mixtures were prepared by varying the graphene oxide (30, 60, 90 and 120 ppm). The nanofuel blend NSME25B10GO90 displayed an enhancement in the brake thermal efficiency (BTE) and a reduction in brake-specific fuel consumption (BSFC) at maximum load due to high catalytic activity and the enhanced microexplosion phenomenon developed by graphene oxide nanoparticles. The heat release rate (HRR), in-cylinder temperature increased, while exhaust gas temperature (EGT) decreased. Smoke, hydrocarbon (HC), carbon monoxide (CO2) and carbon monoxide (CO) emissions also fell, in a trade-off with marginally increased NOx, for all nanofuel blends, compared with Nigella sativa biodiesel. The results obtained indicates that 90 ppm of graphene oxide nanoparticles and 10% n-butanol in Nigella sativa biodiesel are comparable with diesel fuel.

Distinctive Morphology Modifiers for Polymer Blends: Roles of Asymmetric Janus Nanoparticles during Phase Separation.

Janus nanoparticles (JPs), which are anisotropic nanoparticles with multiple constituting parts, have been recognized as superior compatibilizers for polymer-blend-based nanocomposites. However, so far, most studies focused on the effects of symmetric JPs on the phase separation dynamics of polymer blends, while the roles of asymmetric JPs during phase separation remain unclear. In this work, the phase separation dynamics of symmetric blends compatibilized by JPs with various compositions was studied by using dissipative particle dynamics (DPD) simulations. It was found that the blends compatibilized by asymmetric JPs tend to undergo morphological transitions from bicontinuous networks to droplets-in-matrix structures at the late stage of phase separation, which is due to the influence of asymmetric JPs on the energetically favored curvature of the interfaces between polymer domains. Such a mechanism is absent for symmetric JPs and other compatibilizers (e.g., triblock copolymers and homogeneous particles) because they lack the unique combination of chemical asymmetry with the particulate nature like the asymmetric JPs. Moreover, it was observed that the asymmetric JPs can stably localize at the interfaces and act as efficient compatibilizers only when the fraction of the minor constituent part exceeds a critical value. These findings not only shed light upon the roles of asymmetric JPs as compatibilizers but also indicate a promising strategy for designing polymer-blend-based nanocomposites with tailor-made structures.

Microwave-Assisted Growth of Silver Nanoparticle Films with Tunable Plasmon Properties and Asymmetrical Particle Geometry for Applications as Radiation Sensors

We report a simple and fast microwave-assisted method to grow silver nanoparticle films with tunable plasmon resonance band. Microwaving time controls nucleation and growth as well as particle agglomeration, cluster formation, particle morphology, and the plasmonic properties. Films produced with times shorter than 30 s presented a single well-defined plasmon resonance band (~ 400 nm), whereas films produced with times longer than 40 s presented higher wavelength resonances modes (> 500 nm). Plasmon band position and intensity can be easily tuned by controlling microwaving time and power. SEM and AFM images suggested the growth of asymmetrical silver nanoparticles. Simulated extinction spectra considering particles as spheres, hemispheres, and spherical caps were performed. The films were employed to enhance the sensitivity of ionizing radiation detectors assessed by optically stimulated luminescence (OSL) via plasmon-enhanced luminescence. By tuning the plasmon resonance band to overlap with the OSL stimulation (530 nm), luminescence enhancements of greater than 100-fold were obtained, demonstrating the importance of tuning the plasmon resonance band to maximize the OSL intensity and detector sensitivity. This versatile method to produce silver nanoparticle films with tunable plasmonic properties is a promising platform for developing small-sized radiation detectors and advanced sensing technologies.

Multi-field-coupling energy conversion for flexible manipulation of graphene-based soft robots

Soft robots enabling controllable movement in a predicable manner have attracted enormous research interests. However, current researches on soft robots are mainly limited to single actuation mode, and thus complex and multidimensional motility is significantly limited. Here, we propose and demonstrate for the first time a multi-field-coupling energy conversion strategy for flexible manipulation of soft robots, by which 3D-positioning, rotating, levitating, capturing and releasing of a small object by a smart claw are synergistically realized via magnetic, ultrasonic, humidity and light fields. The essence of the strategy is coupling design of the robot compositional materials that can convert energy from different fields into efficient mechanical works. As a typical example, we developed a magnetic-field-assisted gradient assembly method for preparing asymmetric Fe3O4 nanoparticles (NPs) and graphene oxide (GO) composite film. The asymmetric distribution of Fe3O4 NPs in GO leads to an reasonable mechanical stiffness and alters the water adsorption capability of the two sides, which not only imparts multi-responsiveness but also suitably addresses the problem of interlayer detachment in the case of bimorph actuators. The robust soft robots demonstrate good durability, revealing great potential for developing advanced robotic systems that permit direct conversion of multi-field energies to mechanical works.

Antibacterial and anticancer activities of asymmetric lollipop-like mesoporous silica nanoparticles loaded with curcumin and gentamicin sulfate

Asymmetric mesoporous silica nanoparticles with anisotropic geometry and dual-compartments are highly desired for loading and release of dual-drugs in separated storage spaces. In this study, an asymmetric lollipop-like mesoporous silica nanoparticle Fe3O4@SiO2&EPMO (EPMO = ethane bridged periodic mesoporous organosilica) was successfully developed via an anisotropic epitaxial growth strategy. The asymmetric nanoparticles show a uniform lollipop shape with a head of spherical Fe3O4@SiO2 core-shell that is 200 nm in diameter and a tail of EPMO nanorods with a length of ∼90 nm, and a specific surface area of ∼650.3 m2 g−1. Most importantly, the asymmetric nanoparticles possess the unique dual independent (hydrophilic/hydrophobic) spaces with good loading capacities and are significantly more efficient for cancer cell killing than pure drug based on in vitro studies. Additionally, the dual-drug-loaded nanoparticles exhibited excellent antibacterial activity.

In Situ Production of Ag/Polymer Asymmetric Nanoparticles via a Powerful Light-Driven Technique.

As a rapid, controllable, and easily transferrable approach to the preparation of antimicrobial nanoparticle systems, a one-step, light-driven procedure was developed to produce asymmetric hybrid inorganic-organic nanoparticles (NPs) directly from a homogeneous Ag/polymer mixture. An amphiphilic triblock polymer was designed and synthesized to build biocompatible NPs, consisting of poly(ethylene oxide) (PEO), carboxylic acid-functionalized polyphosphoester (PPE), and poly(l-lactide) (PLLA). Unexpectedly, snowman-like asymmetric nanostructures were subsequently obtained by simply loading silver cations into the polymeric micelles together with purification via centrifugation. With an understanding of the chemistry of the asymmetric NP formation, a controllable preparation strategy was developed by applying UV irradiation. A morphology transition was observed by transmission electron microscopy over the UV irradiation time, from small silver NPs distributed inside the micelles into snowman-like asymmetric NPs, which hold promise for potential antimicrobial applications with their unique two-stage silver release profiles.

Free-Standing 2D Janus Gold Nanoparticles Monolayer Film with Tunable Bifacial Morphologies via the Asymmetric Growth at Air-Liquid Interface.

Large scaled two-dimensional free-standing monolayer films of gold nanoparticles show distinctive optical, electrical, and chem-physical propertie making them a new class of advanced plasmonic materials differing from bulk materials and individual nanoparticles in solution. The conventional 2D gold nanoparticle films usually possess symmetric structures and identical properties of gold nanoparticles on both sides. Herein, we developed an easy and efficient approach to construct a new type of free-standing 2D gold nanoparticle monolayer film with asymmetric gold nanoparticle structures and functions, called a 2D Janus gold nanoparticle film. The remarkable feature of our method is the subsequent asymmetric growth on one side of the interfacial self-assembled gold nanoparticle monolayer film at the air-liquid interface. It is very easy to control the morphology of the Janus film by simply and precisely adjusting the size and shape of the gold nanoparticles on the top side, and selectively tuning the structure and composition on the bottom side of the film by growing gold nanoparticles or other noble metals such as Ag, Pt, and Pd. Unlike the conventionally prepared Janus films at solid substrate that require long-time etching and transfer procedures, other features of our method include the short time in which the interfacial self-assembly and the subsequent asymmetric growth are completed as well as the easily transferable property of the Janus film onto different substrates, such as quartz glass sheets, silicon wafers, and PDMS. The obtained Janus gold nanoparticle film shows asymmetric wettabilities, optical properties, and surface-enhanced Raman scattering (SERS) effects, which is promising for a range of potential applications in optical devices, sensors, and asymmetric catalysis.

Quantitative 3D Characterization of Elemental Diffusion Dynamics in Individual Ag@Au Nanoparticles with Different Shapes

Anisotropic bimetallic nanoparticles are promising candidates for plasmonic and catalytic applications. Their catalytic performance and plasmonic properties are closely linked to the distribution of the two metals, which can change during applications in which the particles are exposed to heat. Due to this fact, correlating the thermal stability of complex heterogeneous nanoparticles to their microstructural properties is of high interest for the practical applications of such materials. Here, we employ quantitative electron tomography in high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) mode to measure the 3D elemental diffusion dynamics in individual anisotropic Au-Ag nanoparticles upon heating in situ. This approach allows us to study the elemental redistribution in complex, asymmetric nanoparticles on a single particle level, which has been inaccessible to other techniques so far. In this work, we apply the proposed method to compare the alloying dynamics of Au-Ag nanoparticles with different shapes and compositions and find that the shape of the nanoparticle does not exhibit a significant effect on the alloying speed whereas the composition does. Finally, comparing the experimental results to diffusion simulations allows us to estimate the diffusion coefficients of the metals for individual nanoparticles.

Directed Nanoparticle Assembly through Polymer Crystallization.

Nanoparticles can be assembled into complex structures and architectures by using a variety of methods. In this review, we discuss recent progress of using polymer crystallization (particularly polymer single crystals, PSCs) to direct nanoparticle assembly. PSCs have been extensively studied since 1957. Mainly appearing as quasi-two-dimensional (2D) lamellae, PSCs are typically used as model systems to determine polymer crystalline structures, or as markers to investigate the crystallization process. Recent research has demonstrated that they can also be used as nanoscale functional materials. Herein, we show that nanoparticles can be directed to assemble into complex shapes by using in situ or ex situ polymer crystal growth. End-functionalized polymers can crystallize into 2D nanosheet PSCs, which are used to conjugate with complementary nanoparticles, leading to a nanosandwich structure. These nanosandwiches can find interesting applications for catalysis, surface-enhanced Raman spectroscopy, and nanomotors. Dissolution of the nanosandwich leads to the formation of Janus nanoparticles, providing a unique method for asymmetric nanoparticle synthesis.

Photoluminescence Emission and Raman Vibration Properties of Asymmetric Nanoparticle ZnO Doped Mn2+ Fabricated by a Solvothermal Method

In this study, ZnO doped Mn2+ nanoparticle with hexagonal wurtzite phase was fabricated by a solvothermal method where various contents of Mn ion were in situ doped in ZnO nanostructure. The crystal structure and morphological properties were investigated by X-ray diffractometry, Raman spectroscopy and transmission electron microscopy. The photoluminescence (PL) was measured at room temperature showed red-shift of near-band-to-band emission and the evolution of visible emissions in the doped samples. This work analyzed the PL characteristics of synthesized samples and revealed the role of the dopant Mn2+ on defect states of ZnO.

Shape mediated splenotropic delivery of buparvaquone loaded solid lipid nanoparticles.

Buparvaquone (BPQ)-loaded asymmetric solid lipid nanoparticles (SLN) prepared by a modified nanoprecipitation method were evaluated for splenotropic drug delivery. BPQ SLN exhibited an average particle size of 650.28 ± 6.75nm with polydispersity index ≤ 0.3, entrapment efficiency of 96.57 ± 0.190%, and drug loading of 24.63 ± 0.042%. Scanning electron microscopy (SEM) revealed elongated particles with flattened and rounded edges. Aspect ratio, an important determinant of asymmetricity of the BPQ SLN, measured as the ratio of average length (1143 ± 0.083nm) to width (419 ± 0.031nm) was found to be 2.727 ± 0.19. The hemolytic potential of 10.86 ± 0.04% and good serum stability suggested feasibility for intravenous administration. 99mTc-labeled BPQ SLN revealed high radiolabeling efficiency (> 95%) and good stability. Intravenous administration in mice revealed > 75% accumulation in the reticuloendothelial system organs. The percent radioactivity per gram of organ was in the order spleen > kidney > lungs > liver > lymph nodes, with high splenic accumulation and significantly lower concentration in the liver. An astoundingly high spleen/liver ratio with a maximum of 11.94 ± 1.37 at 3h, which confirmed high splenic uptake is attributed to Kupffer cell bypass. Other factors contributing to splenotropy are the rigidity and the low molecular weight of the lipid in the BPQ SLN which enabled translocation of the particles into the splenic pulp. Our study proposes asymmetric BPQ SLN as a promising splenotropic delivery system for improved efficacy in theileriosis, a spleen resident infection.

Molecular Programming of Biodegradable Nanoworms via Ionically Induced Morphology Switch toward Asymmetric Therapeutic Carriers.

Engineering biodegradable nanostructures with precise morphological characteristics is a key objective in nanomedicine. In particular, asymmetric (i.e., nonspherical) nanoparticles are desirable due to the advantageous effects of shape in a biomedical context. Using molecular engineering, it is possible to program unique morphological features into the self-assembly of block copolymers (BCPs). However, the criteria of biocompatibility and scalability limit progress due to the prevalence of nondegradable components and the use of toxic solvents during fabrication. To address this shortfall, a robust strategy for the fabrication of morphologically asymmetric nanoworms, comprising biodegradable BCPs, has been developed. Modular BCPs comprising poly (ethylene glycol)-block-poly(caprolactone-gradient-trimethylene carbonate) (PEG-PCLgTMC), with a terminal chain of quaternary ammonium-TMC (PTMC-Q), undergo self-assembly via direct hydration into well-defined nanostructures. By controlling the solution ionic strength during hydration, particle morphology switches from spherical micelles to nanoworms (of varying aspect ratio). This ionically-induced switch is driven by modulation of chain packing with salts screening interchain repulsions, leading to micelle elongation. Nanoworms can be loaded with cytotoxic cargo (e.g., doxorubicin) at high efficiency, preferentially interact with cancer cells, and increase tumor penetration. This work showcases the ability to program assembly of BCPs and the potential of asymmetric nanosystems in anticancer drug delivery.

Effect of size and charge asymmetry on aggregation kinetics of oppositely charged nanoparticles

We report a theoretical and experimental study of the aggregation kinetics of oppositely charged nanoparticles. Kinetic Monte Carlo simulations are performed for symmetric, charge-asymmetric and size-asymmetric systems of oppositely charged nanoparticles. Simulation results show that both the weight and number average aggregate size kinetics exhibit power law scaling with different exponents for small and intermediate time of evolution. The qualitative behavior of the symmetric and the size asymmetric system are the same, but the charge asymmetric system shows anomalous behavior for intermediate to high particle concentrations. We also observe a strong dependence of power law exponents on the particle concentration. Radius of gyration of the cluster that indicates how nanoparticles inside a cluster are distributed around the center of mass of the cluster shows a non-monotonic time evolution with pronounced peak at higher particle concentration. The dependence of particle concentration on aggregation kinetics as observed by predictive numerical simulation is further verified experimentally by monitoring the time evolution of aggregate size of nanoparticles assemblies of Poly (methacrylic acid) (PMMA) nanoparticles functionalized with oppositely charged ligands. These size and charge tunable asymmetric polymeric nanoparticles were synthesized by modified miniemulsion technique. The integrated approach for studying nanoparticles aggregation as described here renders new insights into super structure formation and morphology optimization which can be potentially useful in the design of new materials, such as organic photovoltaics.

Liposomes with asymmetric bilayers produced from inverse emulsions for nucleic acid delivery

Asymmetrical lipid nanoparticles are interesting nanocarriers for charged molecules, like nucleic acids. They promise control over inner and outer charge. High charge density on the inside is favourable for efficient condensation and charge neutralisation of highly charged biopharmaceuticals, while a neutral or slightly negative outer layer promotes biocompatibility. The main goal of this work was the development and characterisation of asymmetric liposomes, prepared using water-in-oil (w/o) nanoemulsions of phospholipids (PLs) and squalene in a centrifugal field. This method enables the control over the lipid composition of each monolayer.Liposomes were prepared by passing PL w/o nanoemulsions through an oil–water interface previously saturated with PLs. We used N-(7-Nitrobenz-2-Oxa-1,3-Diazol-4-yl)-1,2-Dihexadecanoyl-sn-Glycero-3-Phosphoethanolamine (NBD-PE) or N-(7-Nitrobenz-2-Oxa-1,3-Diazol-4-yl)-1,2-Dihexadecanoyl-sn-Glycero-3- phosphocholine (NBD-PC) as a fluorescent marker for either the inner or outer lipid layer and plasmid DNA (pDNA) as nucleic acid payload. The final liposomes had sizes below 200 nm and polydispersity indexes of 0.3 and had a bilayer asymmetry of 70%, thus shielding the charge of positive PLs in the inner bilayer leaflet. Final formulations were examined using negative staining transmission electron microscopy (TEM). Plasmid encapsulation efficiency of the method was 10–15%. Our results indicate that the w/o nanoemulsion-centrifugation method allows the successful production of liposomes with tailored features for encapsulation of nucleic acid therapeutics.

Time-Tagged Single Photon Counting Examination of Rotation of Receptor-Bound Quantum Dots

Rotation of single membrane receptors can be observed by examination of polarized optical signals from receptor-bound asymmetric nanoparticles such as fluorescent quantum dots (QD) or nanogold. For example, we have examined the slow, hindered rotation of the Type I Fce receptor (FceRI) on 2H3 RBL cells using polarized fluorescence imaging of receptor-bound Qdot655. With imaging methods, only receptor rotational correlation times (RCT) slower than the camera frame time can be examined and suitable low-light cameras typically require 1ms or longer per frame. However, time-resolved phosphorescence anisotropy shows the hydrodynamic RCT of FcεRI to be about 40 μs at 25°C. To examine such rapid reorientation, an alternate approach is to illuminate individual QD on the cell surface with a focused laser beam, collect fluorescence using a confocal detector and direct signals polarized parallel and perpendicular to the laser polarization into separate APD detectors. A time-tagged single photon counter records the channel of each detected photon and its arrival time with a precision of 165 ps. The auto- and cross-correlations of the two signals are calculated directly from arrival times without binning, combined using adjustable constants such as the g-factor, and these constants optimized to obtain the maximum statistical independence between the anisotropy and intensity time-autocorrelation functions (TAC). While RCTs below 1 ns are theoretically accessible, useful rotational information exists only when RCT∗photon count rate ≥ 1. Thus, given photon count rates, our data potentially provide information on RCTs ≥ 20 μs. However, intensity changes due to QD blinking may feed through to some extent into calculated anisotropies and thus slightly distort apparent anisotropy TAC decay shapes. Efforts aimed at removing this possible complication are underway.

Asymmetric bifunctional protein nanoparticles through redesign of self-assembly.

Engineering oligomeric protein self-assembly is an attractive approach to fabricate nanostructures with well-defined geometries, stoichiometry and functions. The homodecamer Brucella Lumazine Synthase (BLS) is a highly stable and immunogenic protein nanoparticle (PNP). Here, we engineered the BLS protein scaffold to display two functions in spatially opposite regions of its structure yielding a Janus-like nanoparticle. An in silico analysis of the BLS head-to-head dimer of homopentamers shows major inter-pentameric interactions located in the equatorial interface. Based on this analysis, two BLS protomer variants were designed to interrupt pentamer self-dimerization and promote heteropentameric dimers. This strategy enabled us to generate a decameric particle with two distinct sides formed by two independent pentamers. The versatility of this new self-assembly nanofabrication strategy is illustrated with two example applications. First, a bifunctional BLS bearing Alexa Fluor 488 fluorophores on one side and sialic acid binding domains on the other side was used for labelling murine and human cells and analyzed by flow cytometry and confocal microscopy. Second, multichromophoric FRET nanoparticles were fabricated and characterized at the single molecule level, showing discrete energy transfer events. The engineered BLS variants constitute a general platform for displaying two functions in a controlled manner within the same PNP with potential applications in various areas such as biomedicine, biotechnology and nanotechnology.

基于非对称纳米颗粒阵列的垂直与平行表面晶格共振

基于非对称纳米颗粒阵列的垂直与平行表面晶格共振