National Science Review最新文献

Despite the discovery of a series of fullerenes and a handful of noncarbon clusters with the typical topology of I _h-C₆₀, the smallest fullerene with a large degree of curvature, C₂₀, and its other-element counterparts are difficult to isolate experimentally. In coinage metal nanoclusters (NCs), the first all-gold fullerene, Au₃₂, was discovered after a long-lasting pursuit, but the isolation of similar silvery fullerene structures is still challenging. Herein, we report a flying saucer-shaped 102-nuclei silver NC (Ag102) with a silvery fullerene kernel of Ag₃₂, which is embraced by a robust cyclic anionic passivation layer of (KPO₄)₁₀. This Ag₃₂ kernel can be viewed as a non-centered icosahedron Ag₁₂ encaged into a dodecahedron Ag₂₀, forming the silvery fullerene of Ag₁₂@Ag₂₀. The anionic layer (KPO₄)₁₀ is located at the interlayer between the Ag₃₂ kernel and Ag₇₀ shell, passivating the Ag₃₂ silvery fullerene and templating the Ag₇₀ shell. The ^t BuPhS^- and CF₃COO^- ligands on the silver shell show a regioselective arrangement with the 60 ^t BuPhS^- ligands as expanders covering the upper and lower of the flying saucer and 10 CF₃COO^- as terminators neatly encircling the edges of the structure. In addition, Ag102 shows excellent photothermal conversion efficiency (η) from the visible to near-infrared region (η = 67.1% ± 0.9% at 450 nm, 60.9% ± 0.9% at 660 nm and 50.2% ± 0.5% at 808 nm), rendering it a promising material for photothermal converters and potential application in remote laser ignition. This work not only captures silver kernels with the topology of the smallest fullerene C₂₀, but also provides a pathway for incorporating alkali metal (M) into coinage metal NCs via M-oxoanions.

Ultrasensitive protein identification is of paramount importance in basic research and clinical diagnostics but remains extremely challenging. A key bottleneck in preventing single-molecule protein sequencing is that, unlike the revolutionary nucleic acid sequencing methods that rely on the polymerase chain reaction (PCR) to amplify DNA and RNA molecules, protein molecules cannot be directly amplified. Decoding the proteins via amplification of certain fingerprints rather than the intact protein sequence thus represents an appealing alternative choice to address this formidable challenge. Herein, we report a proof-of-concept method that relies on residue-resolved DNA barcoding and composition code counting for amplifiable protein fingerprinting (AmproCode). In AmproCode, selective types of residues on peptides or proteins are chemically labeled with a DNA barcode, which can be amplified and quantified via quantitative PCR. The operation generates a relative ratio as the residue-resolved 'composition code' for each target protein that can be utilized as the fingerprint to determine its identity from the proteome database. We developed a database searching algorithm and applied it to assess the coverage of the whole proteome and secretome via computational simulations, proving the theoretical feasibility of AmproCode. We then designed the residue-specific DNA barcoding and amplification workflow, and identified different synthetic model peptides found in the secretome at as low as the fmol/L level for demonstration. These results build the foundation for an unprecedented amplifiable protein fingerprinting method. We believe that, in the future, AmproCode could ultimately realize single-molecule amplifiable identification of trace complex samples without further purification, and it may open a new avenue in the development of next-generation protein sequencing techniques.

[This corrects the article DOI: 10.1093/nsr/nwae057.].