Overcoming the Coupling Dilemma in DNA-Programmable Nanoparticle Assemblies by "Ag+ Soldering"

Assembly and Healing: Capacitive and Conductive Plasmonic Interfacing via a Unified and Clean Wet Chemistry Route

Solution-based nanoparticle assembly represents a highly promising way to build functional metastructures based on a wealth of synthetic nanomaterial building blocks with well-controlled morphology and crystallinity. In particular, the involvement of DNA molecular programming in these bottom-up processes gradually helps the ambitious goal of customizable chemical nanofabrication. However, a fundamental challenge is to realize strong interunit coupling in an assembly toward emerging functions and applications. Herein, we present a unified and clean strategy to address this critical issue based on a H2O2-redox-driven "assembly and healing" process. This facile solution route is able to realize both capacitively coupled and conductively bridged colloidal boundaries, simply switchable by the reaction temperature, toward bottom-up nanoplasmonic engineering. In particular, such a "green" process does not cause surface contamination of nanoparticles by exogenous active metal ions or strongly passivating ligands, which, if it occurs, could obscure the intrinsic properties of as-formed structures. Accordingly, previously raised questions regarding the activities of strongly coupled plasmonic structures are clarified. The reported process is adaptable to DNA nanotechnology, offering molecular programmability of interparticle charge conductance. This work represents a new generation of methods to make strongly coupled nanoassemblies, offering great opportunities for functional colloidal technology and even metal self-healing.

Gold nanoparticle dimer-based immunochromatography for in situ ultrasensitive detection of porcine epidemic diarrhea virus

The low detection sensitivity of lateral-flow immunochromatography assay (LFIA) based on spherical gold nanoparticle (AuNP) limits its wide applications. In the present study, AuNP dimers with strong plasma scattering and robust signal output were synthesized via the Ag ion soldering (AIS) strategy and used as labeled probes in LFIA to boost the sensitivity without any extra operation process and equipment. The established LFIA exhibited high sensitivity with a limit of detection (LOD) of 2.0 × 102 TCID50/mL for PEDV, which provides 50 times higher sensitivity than commercial LFIA based on spherical colloidal gold. In addition, the AuNP dimer-based LFIA showed strong specificity, good reproducibility, high stability, and good accordance to reverse transcription polymer chain reaction (RT-PCR) when detecting 109 clinical samples. Thus, the AuNP dimers is a promising probe for LFIA and the developed AuNP dimer-based LFIA is suitable for the rapid detection of PEDV in the field.

DNA-Condensed Plasmonic Supraballs Transparent to Molecules

DNA nanotechnology offers an unrivaled programmability of plasmonic nanoassemblies based on encodable Watson-Crick basepairing. However, it is very challenging to build rigidified three-dimensional supracolloidal assemblies with strong electromagnetic coupling and a self-confined exterior shape. We herein report an alternative strategy based on a DNA condensation reaction to make such structures. Using DNA-grafted gold nanoparticles as building blocks and metal ions with suitable phosphate affinities as abiological DNA-bonding agents, a seedless growth of spheroidal supraparticles is realized via metal-ion-induced DNA condensation. Some governing rules are disclosed in this process, including kinetic and thermodynamic effects stemming from electrostatic and coordinative forces with different interaction ranges. The supraballs are tailorable by adjusting the volumetric ratio between DNA grafts and gold cores and by overgrowing extra gold layers toward tunable plasmon coupling. Various appealing and highly desirable properties are achieved for the resulting metaballs, including (i) chemical reversibility and fixation ability, (ii) stability against denaturant, salt, and molecular adsorbates, (iii) enriched and continuously tunable plasmonic hotspots, (iv) permeability to small guest molecules and antifoulingness against protein contaminates, and (v) Raman-enhancing and photocatalytic activities. Innovative applications are thus foreseeable for this emerging class of meta-assemblies in contrast to what is achieved by DNA-basepaired ones.

DNA Mold-Based Fabrication of Palladium Nanostructures

DNA origami molds allow a shape-controlled growth of metallic nanoparticles. So far, this approach is limited to gold and silver. Here, the fabrication of linear palladium nanostructures with controlled lengths and patterns is demonstrated. To obtain nucleation centers for a seeded growth, a synthesis procedure of palladium nanoparticles (PdNPs) using Bis(p-sulfonatophenyl)phenylphosphine (BSPP) both as reductant and stabilizer is developed to establish an efficient functionalization protocol of the particles with single-stranded DNA. Attaching the functionalized particles to complementary DNA strands inside DNA mold cavities supports subsequently a highly specific seeded palladium deposition. This provides rod-like PdNPs with diameters of 20-35 nm of grainy morphology. Using an annealing procedure and a post-reduction step with hydrogen, homogeneous palladium nanostructures can be obtained. With the adaptation of the procedure to palladium the capabilities of the mold-based tool-box are expanded. In the future, this may allow a facile adaptation of the mold approach to less noble metals including magnetic materials such as Ni and Co.

Steering DNA Condensation on Engineered Nanointerfaces

DNA has received increasing attention in nanotechnology due to its ability to fold into prescribed structures. Different from the commonly adopted base-pairing strategy, an emerging class of amorphous DNA materials are formed by DNA's abiological interactions. Despite the great successes, a lack of nanoscale nucleation/growth control disables more advanced considerations. This work aims at harnessing the heterogeneous nucleation of metal-ion-glued DNA condensates on nanointerfaces. Upon unveiling key orthogonal factors including solution pH, ionic cross-linkers, and surface functionalities, chemically programmable DNA condensation on nanoparticle seeds is achieved, resembling a famous Stöber process for silica coating. The nucleation rules discovered on individual nanoseeds can be passed on to their dimeric assemblies, where broken spherical symmetry and the existence of interparticle gaps help a regiospecific DNA gelation. The steerable DNA condensation, and the multifunctions from DNA, metal ions, and nanocores, hold a great promise in noncanonical DNA nanotechnology toward novel applications.

Decoupled Roles of DNA-Surfactant Interactions: Instant Charge Inversion, Enhanced Colloidal and Chemical Stabilities, and Fully Tunable DNA Conjugation of Shaped Plasmonic Nanocrystals

Surfactant-dictated syntheses of nanomaterials with well-defined shapes offer an extra dimension of control beyond nanoparticle size and chemical composition on the properties and self-assembly behaviors of colloidal materials. However, the surfactant bilayers on nanocrystals often cause great difficulty toward DNA grafting due to their unfavorable electrostatic charges and dense surface packing. Herein a revisit to this dilemma unveils a rapid charge inversion and enhanced colloidal/chemical stabilities of cationic-bilayer-covered nanocrystals upon DNA adsorption. Decoupling this hidden scenario provides a rationale to significantly improve DNA functionalization of surfactant-capped nanocrystals. Accordingly, fully tunable DNA conjugation (via Au-S bonding) on up to seven classes of surfactant-coated metal nanounits is easily and consistently achievable. The DNA-nanocrystal complexes featuring a continuously variable DNA density function well in DNA-guided nanoassembly. Our method opens the door to a wealth of material building blocks derived by surfactant-directed nanosyntheses toward DNA-programmable, extremely diversified, and highly complicated structures and functions.

Mechano-Nanoswitches for Ultrasound-Controlled Drug Activation

Current pharmacotherapy is challenged by side effects and drug resistance issues due to the lack of drug selectivity. Mechanochemistry-based strategies provide new avenues to overcome the related problems by improving drug selectivity. It is recently shown that sonomechanical bond scission enables the remote-controlled drug release from their inactive parent macromolecules using ultrasound (US). To further expand the scope of the US-controlled drug activation strategy, herein a mechano-responsive nanoswitch for the selective activation of doxorubicin (DOX) to inhibit cancer cell proliferation is constructed. As a proof-of-concept, the synthesis, characterization, and US-responsive drug activation evaluation of the mechano-nanoswitch, which provides a blueprint for tailoring nanosystems for force-induced pharmacotherapy is presented.

Sub-1.5 nm-gapped heterodimeric plasmonic nanomolecules

A whole set of plasmonic nanodimers with prescribed binary compositions are constructed in solution to enable symmetry-broken strong plasmonic coupling.

Preparation of Monolayer Photonic Crystals from Ag Nanobulge-Deposited SiO2 Particles as Substrates for Reproducible SERS Assay of Trace Thiol Pesticide

Surface-enhanced Raman scattering (SERS) greatly increases the detection sensitivity of Raman scattering. However, its real applications are often degraded due to the unrepeatable preparation of SERS substrates. Herein presented is a very facile and cost-effective method to reproducibly produce a novel type of SERS substrate, a monolayer photonic crystal (PC). With a building block of laboratory-prepared monodisperse SiO₂ particles deposited with space-tunable silver nanobulges (SiO₂@nAg), a PC substrate was first assembled at the air-water interface through needle tip flowing, then transferred onto a silicon slide by a pulling technique. The transferred monolayer PCs were characterized by SEM and AFM to have a hexagonal close-packed lattice. They could increase Raman scattering intensity by up to 2.2 × 10⁷-fold, as tested with p-aminothiophenol. The relative standard deviations were all below 5% among different substrates or among different locations on the same substrate. The excellent reproducibility was ascribed to the highly ordered structure of PCs, while the very high sensitivity was attributed to the strong hotspot effect caused by the appropriately high density of nanobulges deposited on SiO₂ particles and by a closed lattice. The PC substrates were validated to be applicable to the SERS assay of trace thiol pesticides. Thiram pesticide is an example determined in apple juice samples at a concentration 10²-fold lower than the food safety standard of China. This method is extendable to the analysis of other Raman-active thiol chemicals in different samples, and the substrate preparation approach can be modified for the fabrication of more PC substrates from other metallic nanobulge-deposited particles rather than silica only.

Attaching DNA to Gold Nanoparticles With a Protein Corona

DNA-functionalized gold nanoparticles (AuNPs) have been widely used in directed assembly of materials, biosensors, and drug delivery. This conjugate may encounter proteins in these applications and proteins may affect not only DNA adsorption but also the function of the attached DNA. Bovine serum albumin (BSA) with many cysteine residues can strongly adsorb on AuNPs and this conjugate showed high colloidal stability against salt, acid and base. Similar protection effects were also observed with a few other common proteins including catalase, hemoglobin, glucose oxidase, and horseradish peroxidase. DNA oligonucleotides without a thiol label can hardly displace adsorbed BSA, and BSA cannot displace pre-adsorbed DNA either, indicating a strongly kinetically controlled system. Thiolated DNA can be attached at a low density on the AuNPs with a BSA corona. The BSA corona did not facilitate the hybridization of the conjugated DNA, while a smaller peptide, glutathione allowed faster hybridization. Overall, proteins increase the colloidal stability of AuNPs, and they do not perturb the gold-thiol bond in the DNA conjugate, although a large protein corona may inhibit the hybridization function of DNA.

Ag Ion Soldering: An Emerging Tool for Sub-nanomeric Plasmon Coupling and Beyond

Self-assembly represents probably the most flexible way to construct metastructured materials and devices from a wealth of colloidal building blocks with synthetically controllable sizes, shapes, and elemental compositions. In principle, surface capping is unavoidable during the synthesis of nanomaterials with well-defined geometry and stability. The ligand layer also endows inorganic building blocks with molecular recognition ability responsible for their assembly into desired structures. In the case of plasmonic nanounits, precise positioning of them in a nanomolecule or an ordered nanoarray provides a chance to shape their electrodynamic behaviors and thereby assists experimental demonstration of modern nanoplasmonics toward practical uses. Despite previous achievements in bottom-up nanofabrication, a big challenge exists toward strong coupling and facile charge transfer between adjacent nanounits in an assembly. This difficulty has impeded a functional development of plasmonic nanoassemblies. The weakened interparticle coupling originates from the electrostatic and steric barriers of ionic/molecular adsorbates to guarantee a good colloidal stability. Such a dilemma is rooted in fundamental colloidal science, which lacks an effective solution. During the past several years, a chemical tool termed Ag ion soldering (AIS) has been developed to overcome the above situation toward functional colloidal nanotechnology. In particular, a dimeric assembly of plasmonic nanoparticles has been taken as an ideal model to study plasmonic coupling and interparticle charge transfer. This Account starts with a demonstration of the chemical mechanism of AIS, followed by a verification of its workability in various self-assembly systems. A further use of AIS to realize postsynthetic coupling of DNA-directed nanoparticle clusters evidences its compatibility with DNA nanotechnology. Benefiting from the sub-nanometer interparticle gap achieved by AIS, a conductive pathway is established between two nanoparticles in an assembly. Accordingly, light-driven charge transfer between the conductively bridged plasmonic units is realized with highly tunable resonance frequencies. These situations have been demonstrated by thermal/photothermal sintering of silica-isolated nanoparticle dimers as well as gap-specific electroless gold/silver deposition. The regioselective silver deposition is then combined with galvanic replacement to obtain catalytically active nanofoci (plasmonic nanogaps). The resulting structures are useful for real time and on-site Raman spectroscopic tracking of chemical reactions in the plasmonic hotspots (nanogaps) as well as for study of plasmon-mediated/field-enhanced catalysis. The Account is concluded by a deeper insight into the chemical mechanism of AIS and its adaption to conformation-rich structures. Finally, AIS-enabled functional pursuits are suggested for self-assembled materials with strongly coupled and easily reshapable physicochemical properties.

3D Lattice Engineering of Nanoparticles by DNA Shells

With the development of structural DNA nanotechnology, DNA has now far exceeded its original function: as a genetic code. It can, in principle, self-assemble into desired shapes with accurate size. Moreover, it can perform as a functional linker to program other materials by grafting DNA onto these materials. Nanoparticles, both inorganic and organic, can now be programmatically assembled into complex 3D superlattices with high order when guided by DNA. By encoding functions into the as-assembled nanoparticles, materials with excellent collective effects may be invented. Here, how nanoparticles with different shapes or functions are successfully fabricated into 3D lattices with the help of DNA shells coated on the surface and how scientists can produce desired lattices by design are reviewed. The cases to achieve dynamic superlattices of nanoparticles by affecting the environment where DNA survives are also discussed.

Chemically modified nanofoci unifying plasmonics and catalysis

Chemical modifiability is achieved for self-assembled plasmonic nanogaps to enable charge transfer plasmon resonance and unified plasmonic and catalytic functions.

A plasmonic nanofocus, often in the form of a nanogap, is capable of concentrating light in a nanometric volume. The greatly enhanced electromagnetic field offers many opportunities in physics and chemistry. However, the lack of a method to fine-tune the chemical activities of the nanofocus has severely limited its application. Here we communicate an intriguing class of chemically modified nanofoci (CMNFs) that are able to address this challenge. Our results successfully demonstrate a possibility to functionalize the nanosized, mass-transport-restricted nanogap (nanofocus) of a dimeric gold nanoparticle assembly with homo-(Au) and heterogeneous (Ag, Pt, and Pd) materials. The as-produced structures with conductive Au and Ag junctions generate a novel form of charge transfer plasmon (CTP) with continuously tunable frequency covering the visible and near-infrared domains. In addition, the Ag materials can be displaced by catalytic Pt and Pd metals while still maintaining a tightly focused electromagnetic field. These hybrid structures with unified catalytic and plasmonic properties enable real-time, on-site probing of catalytic conversions at the nanofocus by plasmon-enhanced Raman scattering. The chemically/optically engineered CMNFs represent the simplest function-integrated nanodevices for plasmonics, sensing, and catalysis. Our work not only realizes chemical CTP reshaping, but also allows chemical functionalization into an intensified plasmonic near-field. The latter may enable unconventional chemical reactions driven by the catalytically functionalized, strongly boosted light field.

Nanosecond-Laser-Based Charge Transfer Plasmon Engineering of Solution-Assembled Nanodimers

The ability to re-engineer self-assembled functional structures with nanometer accuracy through solution-processing techniques represents a big challenge in nanotechnology. Herein we demonstrate that Ag⁺-soldered nanodimers with a steric confinement coating of silica can be harnessed to realize an in-solution nanosecond laser reshaping to form interparticle conductive pathway with finely controlled conductance. The high structural purity of the nanodimers, the rigid silica coating, and the uniform (but still adjustable) sub-1-nm interparticle gap together determine the success of the laser reshaping process. This method is applicable to DNA-assembled nanodimers, and thus promises DNA-based programming toward higher structural complexity. The resulting structures exhibit highly tunable charge transfer plasmons at visible and near-infrared frequencies dictated by the fluence of the laser pulses. Our work provides an in-solution, rapid, and nonperturbative route to realize charge transfer plasmonic coupling along prescribed paths defined by self-assembly, conferring great opportunities for functional metamaterials in the context of chemical, biological, and nanophotonic applications. The ability to continuously control a subnm interparticle gap and the nanomeric width of a conductive junction also provides a platform to investigate modern plasmonic theories involving quantum and nonlocal effects.

Spatial Regulation of Biomolecular Interactions with a Switchable Trident-Shaped DNA Nanoactuator

DNA nanostructures with controllable motions and functions have been used as flexible scaffolds to precisely and spatially organize molecular reactions at the nanoscale. The construction of dynamic DNA nanostructures with site-specifically incorporated functional elements is a critical step toward building nanomachines. Artificial self-assembled DNA nanostructures have also been developed to mimic key biological processes like various small biomolecule- and protein-based functional biochemistry pathways. Here, we report a self-assembled dynamic trident-shaped DNA (TS DNA) nanoactuator, in which biomolecules can be tethered to the three "arms" of the TS DNA nanoactuator. The TS DNA nanoactuator is implemented as the mechanical scaffold for the reconfiguration of fluorescent/quenching molecules and the assembly of gold nanoparticles, which exhibit controlled spatial separation. Furthermore, two enzymes (glucose oxidase and horseradish peroxidase) are attached to the two outer arms of the TS DNA nanoactuator, which show an enhanced cascade reaction efficiency compared to free enzymes. The efficiency of the two-enzyme cascade reaction can be spatially regulated by switching the TS DNA nanoactuator between opened, semiopened, and closed states through adding the "thermodynamic drivers" (fuels or antifuels). This is the first report to precisely modulate the relative position of coupled enzyme with multiple states and only based on one dynamic DNA scaffold. The present TS DNA nanoactuator with multistage conformational transition functionality could be applied as a potential platform to precisely and dynamically control the multienzyme pathways and would broaden the scope of DNA nanostructures in single-molecule biology applications.

Two-stage DNA compaction induced by silver ions suggests a cooperative binding mechanism

The interaction between silver ions and DNA plays an important role in the therapeutic use of silver ions and in related technologies such as DNA sensors. However, the underlying mechanism has not been fully understood. In this study, the dynamics of Ag⁺-DNA interaction at a single-molecule level was studied using magnetic tweezers. AgNO₃ solutions with concentrations ranging from 1 μM to 20 μM led to a 1.4-1.8 μm decrease in length of a single λ-DNA molecule, indicating that Ag⁺ has a strong binding with DNA, causing the DNA conformational change. The compaction process comprises one linear declining stage and another sigmoid-shaped stage, which can be attributed to the interaction mechanism. Considering the cooperative effect, the sigmoid trend was well explained using a phenomenological model. By contrast, addition of silver nanoparticle solution induced no detectable transition of DNA. The dependence of the interaction on ionic strength and DNA concentration was examined via morphology characterization and particle size distribution measurement. The size of the Ag⁺-DNA complex decreased with an increase in Ag⁺ ionic strength ranging from 1 μM to 1 mM. Morphology characterization confirmed that silver ions induced DNA to adopt a compacted globular conformation. At a fixed [AgNO₃]:[DNA base pairs] ratio, increasing DNA concentration led to increased sizes of the complexes. Intermolecular interaction is believed to affect the Ag⁺-DNA complex formation to a large extent.

Pt supraparticles with controllable DNA valences for programmed nanoassembly

Supraparticles are self-limiting nanoparticle ensembles with attractive properties from their unique hierarchical (primary and secondary) structures. Aiming at relieving the bottleneck of the very limited material building blocks in DNA nanotechnology, we herein demonstrate Pt-based supraparticles as catalytic materials for valence-controllable and high density DNA functionalizations toward DNA-programmed nanoassembly.

Freeze the Moment: High Speed Capturing of Weakly Bonded Dynamic Nanoparticle Assemblies in Solution by Ag Ion Soldering

Despite the versatile forms of colloidal aggregates, these spontaneously formed structures are often hard to find a suitable application in nanotechnology and materials science. A determinate reason is the lack of a suitable method to capture the transiently formed and quickly evolving colloidal structures in solution. To address this challenge, a simple but highly efficient strategy is herein reported to capture the dynamic and metastable colloidal assemblies formed in an aqueous or nonaqueous solution. This process takes advantage of a recently developed Ag ion soldering reaction to realize a rapid fixation of as-formed metastable assemblies. This method works efficiently for both solid (3D) nanoparticle aggregates and weakly bonded fractal nanoparticle chains (1D). In both cases, very high capturing speed and close to 100% efficiency are achieved to fully retain a quickly growing structure. The soldered nanochains further enable a fabrication of discrete, uniform, and functionalizable nanoparticle clusters with enriched linear conformation by mechanical shearing, which would otherwise be difficult to make. The captured products are water dispersible and mechanically robust, favoring an exploration of their properties toward possible applications. The work paves a way to previously untouched aspects of colloidal science and thus would create new chances in nanotechnology.

Self-Assembly of Colloidal Nanocrystals: From Intricate Structures to Functional Materials

Chemical methods developed over the past two decades enable preparation of colloidal nanocrystals with uniform size and shape. These Brownian objects readily order into superlattices. Recently, the range of accessible inorganic cores and tunable surface chemistries dramatically increased, expanding the set of nanocrystal arrangements experimentally attainable. In this review, we discuss efforts to create next-generation materials via bottom-up organization of nanocrystals with preprogrammed functionality and self-assembly instructions. This process is often driven by both interparticle interactions and the influence of the assembly environment. The introduction provides the reader with a practical overview of nanocrystal synthesis, self-assembly, and superlattice characterization. We then summarize the theory of nanocrystal interactions and examine fundamental principles governing nanocrystal self-assembly from hard and soft particle perspectives borrowed from the comparatively established fields of micrometer colloids and block copolymer assembly. We outline the extensive catalog of superlattices prepared to date using hydrocarbon-capped nanocrystals with spherical, polyhedral, rod, plate, and branched inorganic core shapes, as well as those obtained by mixing combinations thereof. We also provide an overview of structural defects in nanocrystal superlattices. We then explore the unique possibilities offered by leveraging nontraditional surface chemistries and assembly environments to control superlattice structure and produce nonbulk assemblies. We end with a discussion of the unique optical, magnetic, electronic, and catalytic properties of ordered nanocrystal superlattices, and the coming advances required to make use of this new class of solids.

"Flash" preparation of strongly coupled metal nanoparticle clusters with sub-nm gaps by Ag+ soldering: toward effective plasmonic tuning of solution-assembled nanomaterials

Noble metal nanoparticle oligomers are important in applications including plasmonics, catalysis, and molecular sensing. These nanostructural units featuring abundant inter-particle junctions are helpful for a physical/chemical understanding of structure-activity relationships of self-assembled metamaterials. A simple, rapid, and potentially general strategy for the preparation of monodisperse nanoparticle clusters in a homogeneous solution is highly desired for fundamental research toward liquid metamaterials and chemical/biological applications, but this is however very challenging. Here we report an Ag⁺ soldering strategy to prepare strongly coupled plasmonic (Au) and catalytic (Pt, Au@Pd (Au core with a Pd shell)) nanoparticle clusters almost instantly (<1 min) in a solution without special synthetic efforts, complicated surface decorations, or structure-directing templates. The resulting clusters are isolatable by agarose gel electrophoresis, resulting in mechanically stable products in high purity. The optical extinctions of Au nanodimers (the simplest and most basic form of a coupled structure) exhibit prominent longitudinal plasmonic coupling for nanoparticles down to 13.3 nm in diameter. Theoretical simulations attribute the strong coupling to the existence of a sub-nm gap (c.a. 0.76 nm) between soldered particles, suggesting an ideal (stable, soluble, monodisperse, and weakly passivated) substrate for surface enhanced Raman scattering (SERS) applications.

Chemoresponsive Colloidosomes via Ag⁺ Soldering of Surface-Assembled Nanoparticle Monolayers

Colloidosomes with a hollow interior and a porous plasmonic shell are highly desired for many applications including nanoreactors, surface-enhanced Raman scattering (SERS), photothermal therapy, and controlled drug release. We herein report a silica nanosphere-templated electrostatic self-assembly in conjunction with a newly developed Ag(+) soldering to fabricate gold colloidosomes toward multifunctionality and stimuli-responsibility. The gold colloidosomes are capable of capturing a nanosized object and releasing it via structural dissociation upon responding to a biochemical input (GSH, glutathione) at a concentration close to its cellular level. In addition, the colloidosomes have a tunable nanoporous shell composed of strongly coupled gold nanoparticles, which exhibit broadened near-infrared plasmon resonance. These features along with the simplicity and high tunability of the fabrication process make the gold colloidosomes quite promising for applications in a chemical or cellular environment.