Templated by DNA origami, plasmonic gold nanorods (AuNRs) could be assembled into complex nanostructures with strong chiroptical activities. However, it is still not clear how the plasmonic chirality of a complex nanostructure matters with its daughter structural components. Here, we rationally design and fabricate a series of AuNR trimers and their daughter AuNR dimers. Strikingly, we corroborate by circular dichroism spectroscopy that the plasmonic chirality of asymmetrical AuNR trimers is a nearly perfect summation of the chiroptical response of all their constituent dimeric components. Our results provide fundamental insight into the origin of the plasmonic chirality of complex nanostructures.

Au nanoparticles (NPs) possess unique physicochemical and optical properties, showing great potential in biomedical applications. Diagnostic spectroscopy utilizing varied Au NPs has become a precision tool of in vitro and in vivo diagnostic for cancer and other specific diseases. In this review, we tried to comprehensively introduce the remarkable optical properties of Au NPs, including localized surfaces plasmon resonance (LSPR), surface-enhanced Raman scattering (SERS), and metal-enhanced fluorescence (MEF). Then, we highlighted the excellent works using Au NPs for optical diagnostic applications. Ultimately, the challenges and future perspective of using Au NPs for optical diagnostic were discussed.

Nonviral delivery of nucleic acids to the cell nucleus typically requires chemical methods that do not guarantee specific delivery (e.g., transfection agent) or physical methods that may require extensive fabrication (e.g., microfluidics) or an elevated pressure (e.g., 10 5 Pa for microneedles). We report a method of delivering oligonucleotides to the nucleus with high specificity (relative to the cytosol) by synergistically combining chemical and physical approaches. Particularly, we demonstrate that DNA oligonucleotides appended with a polythymidine [poly(T)] segment (chemical) profusely accumulate inside the nucleus when the cells are under gentle compression imposed by the weight of a single glass coverslip (physical; ∼2.2 Pa). Our "compression-cum-poly(T)" delivery method is simple, can be generalizable to three "hardto-transfect" cell types, and does not induce significant levels of cytotoxicity or long-term oxidative stress to the treated cells when provided the use of suitable compression times and oligonucleotide concentrations. In bEnd.3 endothelial cells, compression-aided intranuclear delivery of poly(T) is primarily mediated by importin β and nucleoporin 62. Our method significantly enhances the intranuclear delivery of antisense oligonucleotides to bEnd.3 endothelioma cells and the inhibition of two target genes, including a reporter gene encoding the enhanced green fluorescent protein and an intranuclear lncRNA oncogene (metastasis-associated lung adenocarcinoma transcript 1), when compared with delivery without gentle compression or poly(T) attachment. Our data underscore the critical roles of pressure and nucleotide sequence on the intranuclear delivery of nucleic acids.

Chiral nanostructures are asymmetric nanoarchitectures that cannot be superimposed with their mirrored-symmetric counterparts, which have attracted considerable attention due to their special photophysical properties and potential applications in plasmonics, spectroscopy and nanosensors. In particular, Self-Assembly of chiral nanostructures with symmetric or asymmetric objects might exhibit exceptional optical activity because those chiral superstructures can manipulate chiral states of light that leads to circular dichroism (CD) effect. This review highlights recent advances on the self-assembly of plasmonic chiral superstructures from simpler dimeric, and trimeric chiral nanoassemblies to complicated chiral nanoarchitectures, especially emphasizes the resulted superior optical activity and the corresponding principles.