Plasmonic nanostructures possessing unique and versatile optoelectronic properties have been vastly investigated over the past decade. However, the full potential of plasmonic nanostructure has not yet been fully exploited, particularly with single-component homogeneous structures with monotonic properties, and the addition of new components for making multicomponent nanoparticles may lead to new-yet-unexpected or improved properties. Here we define the term “multi-component nanoparticles” as hybrid structures composed of two or more condensed nanoscale domains with distinctive material compositions, shapes, or sizes. We reviewed and discussed the designing principles and synthetic strategies to efficiently combine multiple components to form hybrid nanoparticles with a new or improved plasmonic functionality. In particular, it has been quite challenging to precisely synthesize widely diverse multicomponent plasmonic structures, limiting realization of the full potential of plasmonic heterostructures. To address this challenge, several synthetic approaches have been reported to form a variety of different multicomponent plasmonic nanoparticles, mainly based on heterogeneous nucleation, atomic replacements, adsorption on supports, and biomolecule-mediated assemblies. In addition, the unique and synergistic features of multicomponent plasmonic nanoparticles, such as combination of pristine material properties, finely tuned plasmon resonance and coupling, enhanced light-matter interactions, geometry-induced polarization, and plasmon-induced energy and charge transfer across the heterointerface, were reported. In this review, we comprehensively summarize the latest advances on state-of-art synthetic strategies, unique properties, and promising applications of multicomponent plasmonic nanoparticles. These plasmonic nanoparticles including heterostructured nanoparticles and composite nanostructures are prepared by direct synthesis and physical force- or biomolecule-mediated assembly, which hold tremendous potential for plasmon-mediated energy transfer, magnetic plasmonics, metamolecules, and nanobiotechnology.

A planar, trivalent phosphorus compound is shown to undergo reversible two-electron redox cycling (P(III)/P(V)) enabling its use as catalyst for a transfer hydrogenation reaction. The trivalent phosphorus compound activates ammonia-borane to furnish a 10-P-5 dihydridophosphorane, which in turn is shown to transfer hydrogen cleanly to azobenzene, yielding diphenylhydrazine and regenerating the initial trivalent phosphorus species. This result constitutes a rare example of two-electron redox catalysis at a main group compound and suggests broader potential for this nonmetal platform to support bond-modifying redox catalysis of the type dominated by transition metal catalysts.

We developed a synthetic strategy to form cyclodextrin-based intrananogap particles (CIPs) with a well-defined ∼1 nm interior gap in a high yield (∼97%), and were able to incorporate 10 different Raman dyes inside the gap using the cyclodextrin-based host–guest chemistry, leading to strong, reproducible, and highly multiplexable surface-enhanced Raman scattering (SERS) signals. The average SERS enhancement factor (EF) for CIPs was 3.0 × 109 with a very narrow distribution of the EFs that range from 9.5 × 108 to 9.5 × 109 for ∼95% of the measured particles. Remarkably, 10 different Raman dyes can be loaded within the nanogap of CIPs, and 6 different Raman dye-loaded CIPs with little spectral overlaps were distinctly detected for cancer cell imaging applications with a single excitation source. Our synthetic strategy provides new platforms in precisely forming plasmonic nanogap structures with all key features for widespread use of SERS including strong signal intensity, reliability in quantification of signal and multiplexing capability.

Photothermal therapy (PTT) exploits nanomaterials with optimal heat conversion and cellular penetration using near-infrared (NIR) laser irradiation. However, current PTT agents suffer from inefficient heat conversion, poor intracellular delivery, and a high dose of probes along with excessive laser irradiation, causing limited therapeutic outcomes. Here, bumpy Au triangular nanoprisms (BATrisms) are developed for increasing the surface area, improving cell penetration, shifting the absorption peak to the NIR region, and enhancing the photothermal conversion efficiency (∼86%). Further, leucine (L)-and lysine (K)-rich cell-penetrating peptides (LK peptides) were employed to largely improve their cellular uptake efficiency. Importantly, a significant in vivo therapeutic efficacy with LK-BATrisms was demonstrated in a triple-negative breast cancer xenograft mice model. A very small dose of LK-BATrism (2.5 μg Au) was enough to exert antitumor efficacy under very low laser power (808 nm, 0.25 W/cm 2 ), causing minimal tissue damages while very efficiently killing cancer cells.

Schizophrenia (SZ) is associated with an increased risk of life-long cognitive impairments, age-related chronic disease, and premature mortality. We investigated evidence for advanced brain ageing in adult SZ patients, and whether this was associated with clinical characteristics in a prospective meta-analytic study conducted by the ENIGMA Schizophrenia Working Group. The study included data from 26 cohorts worldwide, with a total of 2803 SZ patients (mean age 34.2 years; range 18–72 years; 67% male) and 2598 healthy controls (mean age 33.8 years, range 18–73 years, 55% male). Brain-predicted age was individually estimated using a model trained on independent data based on 68 measures of cortical thickness and surface area, 7 subcortical volumes, lateral ventricular volumes and total intracranial volume, all derived from T1-weighted brain magnetic resonance imaging (MRI) scans. Deviations from a healthy brain ageing trajectory were assessed by the difference between brain-predicted age and chronological age (brain-predicted age difference [brain-PAD]). On average, SZ patients showed a higher brain-PAD of +3.55 years (95% CI: 2.91, 4.19; I2 = 57.53%) compared to controls, after adjusting for age, sex and site (Cohen’s d = 0.48). Among SZ patients, brain-PAD was not associated with specific clinical characteristics (age of onset, duration of illness, symptom severity, or antipsychotic use and dose). This large-scale collaborative study suggests advanced structural brain ageing in SZ. Longitudinal studies of SZ and a range of mental and somatic health outcomes will help to further evaluate the clinical implications of increased brain-PAD and its ability to be influenced by interventions.