Multicomponent supramolecular copolymerization promises to construct complex nanostructures with emergent properties. However, even with two monomeric components, various possible outcomes such as self-sorted supramolecular homopolymers, a random (statistical) supramolecular copolymer, an alternate supramolecular copolymer, or a complex supramolecular block copolymer can occur, determined by their intermolecular interactions and monomer exchange dynamics and hence structural prediction is extremely challenging. Herein, we target this challenge and demonstrate unprecedented two-component sequence controlled supramolecular copolymerization by manipulating thermodynamic and kinetic routes in the pathway complexity of selfassembly of the constitutive monomers. Extensive molecular dynamics simulations provided useful mechanistic insights into the monomer exchange rates and free energy of interactions between the monomers that dictate the self-assembly pathway and sequence. The fluorescent nature of core-substituted naphthalene diimide monomers has been further utilized to characterize the three sequences via Structured Illumination Microscopy (SIM).

Supramolecular block copolymerzation with optically or electronically complementary monomers provides an attractive bottomup approach for the non-covalent synthesis of nascent axial organic heterostructures, which promises to deliver useful applications in energy conversion, optoelectronics, and catalysis. However, the synthesis of supramolecular block copolymers (BCPs) constitutes a significant challenge due to the exchange dynamics of non-covalently bound monomers and hence requires fine microstructure control. Furthermore, temporal stability of the segmented microstructure is a prerequisite to explore the applications of functional supramolecular BCPs. Herein, we report the cooperative supramolecular block copolymerization of fluorescent monomers in solution under thermodynamic control for the synthesis of axial organic heterostructures with light-harvesting properties. The fluorescent nature of the core-substituted naphthalene diimide (cNDI) monomers enables a detailed spectroscopic probing during the supramolecular block copolymerization process to unravel a nucleation−growth mechanism, similar to that of chain copolymerization for covalent block copolymers. Structured illumination microscopy (SIM) imaging of BCP chains characterizes the segmented microstructure and also allows size distribution analysis to reveal the narrow polydispersity (polydispersity index (PDI) ≈ 1.1) for the individual block segments. Spectrally resolved fluorescence microscopy on single block copolymerized organic heterostructures shows energy migration and light-harvesting across the interfaces of linearly connected segments. Molecular dynamics and metadynamics simulations provide useful mechanistic insights into the free energy of interaction between the monomers as well as into monomer exchange mechanisms and dynamics, which have a crucial impact on determining the copolymer microstructure. Our comprehensive spectroscopic, microscopic, and computational analyses provide an unambiguous structural, dynamic, and functional characterization of the supramolecular BCPs. The strategy presented here is expected to pave the way for the synthesis of multi-component organic heterostructures for various functions.

Synthesis of supramolecular blockc o-polymers (BCP) with small monomers and predictive sequence requires elegant molecular design and synthetic strategies.H erein we report the unparalleled synthesis of tri-component supramolecular BCPs with tunable microstructure by ak inetically controlled sequential seeded supramolecular polymerization of fluorescent p-conjugated monomers.C ore-substituted naphthalene diimide (cNDI) derivatives with different core substitutions and appended with b-sheet forming peptide side chains providep erfect monomer design with spectral complementarity,p athway complexity and minimal structural mismatcht os ynthesize and characterize the multi-component BCPs.T he distinct fluorescent nature of various cNDI monomers aids the spectroscopic probing of the seeded growth process and the microscopic visualization of resultant supramolecular BCPs using Structured Illumination Microscopy (SIM). Kinetically controlled sequential seeded supramolecular polymerization presented here is reminiscent of the multistep synthesis of covalent BCPs via living chain polymerization. These findings provide ap romising platform for constructing unique functional organic heterostructures for various optoelectronic and catalytic applications.

The discovery of new two-dimensional (2D) perovskite halides has created sensation recently because of their structural diversity and intriguing optical properties. The toxicity of Pb-based perovskite halides led to the development of Pb-free halides. Herein, we have demonstrated a one-pot solution-based synthesis of 2D ultrathin (∼1.78 nm) few-layer (2–4 layers) nanoplates (300–600 nm lateral dimension), nanosheets (0.6–1.5 μm), and nanocrystals of layered Cs3Bi2I9 by varying the reaction temperature from 110 to 180 °C. We have established a mechanistic pathway for the variation of morphology of Cs3Bi2I9 with temperature in the presence of organic capping ligands. Further, we have synthesized the bulk powder of Cs3Bi2I9 by mechanochemical synthesis and liquid-assisted grinding and crystalline ingot by vacuum-sealed tube melting. 2D nanoplates and bulk Cs3Bi2I9 demonstrate optical absorption edge along with excitonic transition. Photoluminescence properties of individual nanoplates were studied by super-resolution fluorescence imaging, which indicated the blinking behavior down to the level of an individual Cs3Bi2I9 nanoplate along with its emission at the far-red region and high photostability.

Bioorthogonal strategies are continuing to pave the way for new analytical tools in biology. Although a significant amount of progress has been made in developing covalent reaction based bioorthogonal strategies, balanced reactivity, and stability are often difficult to achieve from these systems. Alternatively, despite being kinetically beneficial, the development of noncovalent approaches that utilize fully synthetic and stable components remains challenging due to the lack of selectivity in conventional noncovalent interactions in the living cellular environment. Herein, we introduce a bioorthogonal assembly strategy based on a synthetic host-guest system featuring Cucurbit[7]uril (CB[7]) and adamantylamine (ADA). We demonstrate that highly selective and ultrastable host-guest interaction between CB[7] and ADA provides a noncovalent mechanism for assembling labeling agents, such as fluorophores and DNA, in cells and tissues for bioorthogonal imaging of molecular targets. Additionally, by combining with covalent reaction, we show that this CB[7]-ADA based noncovalent interaction enables simultaneous bioorthogonal labeling and multiplexed imaging in cells as well as tissue sections. Finally, we show that interaction between CB[7] and ADA fulfills the demands of specificity and stability that is required for assembling molecules in the complexities of a living cell. We demonstrate this by sensitive detection of metastatic cancer-associated cell surface protein marker as well as by showing the distribution and dynamics of F-actin in living cells.

In a three-dimensional (3D) representation, each protein molecule displays a specific pattern of chemical and topological features, which are altered during its misfolding and aggregation pathway. Generating a recognizable fingerprint from such features could provide an enticing approach not only to identify these biomolecules but also to gain clues regarding their folding state and the occurrence of pathologically lethal misfolded aggregates. We report here a universal strategy to generate a fluorescent fingerprint from biomolecules by employing the pan-selective molecular recognition feature of a cucurbit[7]­uril (CB[7]) macrocyclic receptor. We implemented a direct sensing strategy by covalently tethering CB[7] with a library of fluorescent reporters. When CB[7] recognizes the chemical and geometrical features of a biomolecule, it brings the tethered fluorophore into the vicinity, concomitantly reporting the nature of its binding microenvironment through a change in their optical signature. The photophysical properties of the fluorophores allow a multitude of probing modes, while their structural features provide additional binding diversity, generating a distinct fluorescence fingerprint from the biomolecule. We first used this strategy to rapidly discriminate a diverse range of protein analytes. The macrocyclic sensor was then applied to probe conformational changes in the protein structure and identify the formation of oligomeric and fibrillar species from misfolded proteins. Notably, the sensor system allowed us to differentiate between different self-assembled forms of the disease-specific amyloid-β (Aβ) aggregates and segregated them from other generic amyloid structures with a 100% identification accuracy. Ultimately, this sensor system predicted clinically relevant changes by fingerprinting serum samples from a cohort of pregnant women.

Self-sorting is a spontaneous phenomenon that ensures formation of complex yet ordered multicomponent system and conceptualizes the design of artificial and orthogonally functional compartments. In the present study, we envisage...

Two‐dimensional (2D) lead‐free halide perovskites have generated enormous perception in the field of optoelectronics due to their fascinating optical properties. However, an in‐depth understanding on their shape‐controlled charge‐carrier recombination dynamics is still lacking, which could be resolved by exploring the photoluminescence (PL) blinking behaviour at the single‐particle level. Herein, we demonstrate, for the first time, the synthesis of nanocrystals (NCs) and 2D nanosheets (NSs) of layered mixed halide, Cs3Bi2I6Cl3, by solution‐based method. We applied fluorescence microscopy and super‐resolution optical imaging at single‐particle level to investigate their morphology‐dependent PL properties. Narrow emission line widths and passivation of non‐radiative defects were evidenced for 2D layered nanostructures, whereas the activation of shallow trap states was recognized at 77 K. Interestingly, individual NCs were found to display temporal intermittency (blinking) in PL emission. On the other hand, NS showed temporal PL intensity fluctuations within localized domains of the crystal. In addition, super‐resolution optical image of the NS from localization‐based method showed spatial inhomogeneity of the PL intensity within perovskite crystal.