Precise and rapid monitoring of metabolites in biofluids is a desirable but unmet goal for disease diagnosis and management. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) exhibits advantages in metabolite analysis. However, the low accuracy in quantification of the technique limits its transformation to clinical usage. We report herein the use of Au nanoparticle arrays self-assembled at liquid–liquid interfaces for mass spectrometry (MS)-based quantitative biofluids metabolic profiling. The two-dimensional arrays feature uniformly and closely packed Au nanoparticles with 3 nm interparticle gaps. The experimental study and theoretical simulation show that the arrays exhibit high photothermal conversion and heat confinement effects, which enhance the laser desorption/ionization efficacy. With the nanoscale roughness, the AuNP arrays as laser desorption/ionization substrates can interrupt the coffee-ring effect during droplet evaporation. Therefore, high reproducibility (RSD <5%) is obtained, enabling accurate quantitative analysis of diverse metabolites from 1 μL of biofluids in seconds. By quantifying glucose in the cerebrospinal fluid (CSF), it allows us to identify patients with brain infection and rapidly evaluate the clinical therapy response. Consequently, the method shows potential in advanced metabolite analysis and biomedical diagnostics.

Aseries of molecular metalla[2]catenanes featuring Cp*Ir vertices have been prepared by the template-free, coordination-driven self-assembly of dinuclear iridium acceptors and 1,5-bis[2-(4-pyridyl)ethynyl]anthracene donors.T he metalla[2]catenanes were formed by using as trategically selected linker type that is capable of participating in sandwich-type p-p stackingi nteractions.I nt he solid state,t he [2]catenanes adopt two different configurations depending on the halogen atoms at the dinuclear metal complex bridge. Altering the solvent or the concentration, as well as the addition of guest molecules,e nabled controlled transformations between metalla[2]catenanes and tetranuclear metallarectangles.Scheme 1. Synthesis of the metallarectangles 1(OTf) 4 , 2a(OTf) 4 -4a(OTf) 4 ,a nd the metalla[2]catenanes 2(OTf) 8 -4(OTf) 8 .

Although reversible photo-dimerization or oxygenation of anthracene and its derivatives is a common reaction, light-initiated reversible conversion of endoperoxide organometallic frameworks has only rarely been addressed. Herein, a series of tetranuclear organometallic macrocycles, [Cp*Rh(μ-CO-κO)](BP4VA)(OTf) (4), [Cp*Rh(BiBzIm)](BP4VA)(OTf) (5), and [Cp*Rh(DHBQ)](BP4VA)(OTf) (6), were obtained in good yields from the reactions of the binuclear half-sandwich rhodium precursors [Cp*Rh(μ-CO-κO)Cl] (1), [Cp*Rh(BiBzIm)Cl] (2), and [Cp*Rh(DHBQ)Cl] (3) with the 9,10-bis((E)-2-(pyrid-4-yl)vinyl)anthracene (BP4VA) ligand. The photochemical reaction of these metallarectangles was investigated by NMR and UV/vis spectroscopy. We have demonstrated that complexes 4, 5, and 6 can be reversibly and nearly quantitatively converted to the macrocyclic endoperoxides 4-O2, 5-O2, and 6-O2. Meanwhile, the structure of the endoperoxide photoproducts was unambiguously confirmed by H/C NMR spectroscopy, IR spectroscopy, elemental analyses, and X-ray crystallography.

The construction of metal–organic cages (MOCs) with specific structures and fluorescence sensing properties is of much importance and challenging. Herein, a novel phenanthroline-based metal–organic cage, [Cd3L3·6MeOH·6H2O] (1), was synthesized by metal-directed assembly of the ligand 3,3′-[(1E,1′E)-(1,10-phenanthroline-2,9-diyl)­bis­(ethene-2,1-diyl)]­dibenzoic acid (H2L) and CdI2 using a solvothermal method. According to single-crystal X-ray analysis, cage 1 exhibits a rare trefoil-shaped structure. Meanwhile, the discrete MOCs are further stacked into a 3D porous supramolecular structure through abundant intermolecular C–H···O interactions. Additionally, through exploration of fluorescence sensing on cations, anions, and antibiotics in aqueous solution, the experimental results indicate that cage 1 has excellent fluorescence sensing abilities for Fe3+, Cr2O7 2–, and nitrofuran and nitroimidazole antibiotics. The sensing ability of 1 remains unaltered for five cycles toward all analytes. The above results suggested that cage 1 can be considered a potential multiple sensor for the detection of Fe3+, Cr2O7 2–, and some antibiotics.