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Novel cell-targeting ligand structures are constructed with a spikey core scaffold, where multiple copies of coiled-coil peptide nanorods are conjugated on the surface of a peptide nanosheet. Clustering of carbohydrate and aptamer ligands at the end of the coiled coils optimizes ligand accessibility to cell-surface receptors. Display of the ligand-coil conjugates on the nanosheet generates a patchy ligand pattern bearing two levels of multivalency. With the ligand-scaffold system, high-avidity cell targeting is realized using fewer ligands than ever, which facilitates future applications in cell detection and drug delivery.

Fluorescent molecular sensors offer a sensitive and straightforward approach to monitoring biologically or environmentally important targets. However, obtaining high-performance chemosensors are still challenging in terms of laborious synthesis and low success rate. Herein we report a general and efficient strategy for fabrication of complex fluorescent chemosensors. Noncovalent synthesis of supramolecular sensors was realized by self-assembly of structurally simple subunits bearing hydrogen-bonding linkers. Based on the selected use of three recognition subunits and three signalling subunits, an array of fluorescent sensory co-assemblies with different subunits combination patterns were fabricated for sensitive detection of bisulfite, saccharides, carbon dioxide or chemical warfare agents. The multiplicity and ratios of these subunits can be flexibly adjusted to obtain desirable functions such as signal amplification, ratiometric responses and simultaneous multitarget monitoring.

An efficient approach for fabrication of novel near-infrared (NIR) absorbing materials has been developed based on stabilization of chromogenic radicals in lipid membranes. Compared with the closed-shell molecules, radicals or radical ions of organic chromophores usually display remarkably red-shifted absorption. However, stabilization and functionalization of these radicals is still a challenging task. Herein, biomimetic membranes were employed as a platform for stabilization and convenient functionalization of chromogenic radicals. NIR optical vesicles can be facilely formed by co-assembly of radical-dominated supramolecular chromophores with surfactants in aqueous solution. The as-formed dye-interbedded vesicles with biomimetic membrane surfaces displays strong NIR absorption and electron spin resonance signals, sensitive photoacoustic response upon NIR excitation, and minimal nonspecific interaction with biological macro-molecules. Furthermore, doping of the chromogenic interlayers to optimize the optical properties and modification of the membrane surfaces for functionalization towards bioanalytical applications can be carried out under ambient conditions.

A structurally simple and easily synthesized anthracene derivative bearing a barbituric acid moiety (AnB) was developed as a novel fluorescent chemosensor for Hg2+ in terms of specific ratiometric fluorescence response to Hg2+ in aqueous solution via the formation of Hg2+–AnB coordination polymers.