We report selective electrocatalytic reduction of carbon dioxide to carbon monoxide on gold nanoparticles (NPs) in 0.5 M KHCO3 at 25 °C. Among monodisperse 4, 6, 8, and 10 nm NPs tested, the 8 nm Au NPs show the maximum Faradaic efficiency (FE) (up to 90% at -0.67 V vs reversible hydrogen electrode, RHE). Density functional theory calculations suggest that more edge sites (active for CO evolution) than corner sites (active for the competitive H2 evolution reaction) on the Au NP surface facilitates the stabilization of the reduction intermediates, such as COOH*, and the formation of CO. This mechanism is further supported by the fact that Au NPs embedded in a matrix of butyl-3-methylimidazolium hexafluorophosphate for more efficient COOH* stabilization exhibit even higher reaction activity (3 A/g mass activity) and selectivity (97% FE) at -0.52 V (vs RHE). The work demonstrates the great potentials of using monodisperse Au NPs to optimize the available reaction intermediate binding sites for efficient and selective electrocatalytic reduction of CO2 to CO.

Nanovehicles can efficiently carry and deliver anticancer agents to tumour sites. Compared with normal tissue, the tumour microenvironment has some unique properties, such as vascular abnormalities, hypoxia and acidic pH. There are many types of cells including tumour cells, macrophages, immune and fibroblasts cells, fed by defective blood vessels in the solid tumour. Exploiting the tumour microenvironment can benefit the design of nanoparticles for enhanced therapeutic effectiveness. In this review article, we summarized the recent progress in various nanoformulations for cancer therapy, with special emphasis on tumour microenvironment stimuli-responsive ones. Numerous tumour microenvironment modulation strategies with promising cancer therapeutic efficacy have also been highlighted. Future challenges and opportunities of design consideration are also discussed in details. We believe that these tumour microenvironment modulation strategies offer a good chance for the practical translation of nanoparticle formulas into clinic.

Hierarchical assembling of gold nanoparticles (GNPs) allows one to engineer the localized surface plasmon resonance (LSPR) peaks to the near-infrared (NIR) region for enhanced photothermal Therapy (PTT). Herein we report a novel theranostic platform based on biodegradable plasmonic gold nanovesicles for photoacoustic (PA) Imaging and PTT. The disulfide bond (S-S) termed PEG-b-PCL block copolymer graft allows dense packing of GNPs during the assembly process and induces ultra-strong plasmonic coupling effect between adjacent GNPs. The strong NIR absorption induced by plasmon coupling and very high photothermal conversion efficiency (η= 37 %) enable simultaneous thermal/PA imaging and enhanced PTT efficacy with improved clearance of the dissociated particles after the completion of PTT. These vesicle-architectures assembling of various nanocrystals with tailored optical, magnetic, and electronic properties opens new possibilities for constructing multifunctional biodegradable platforms for biomedical applications, particularly in cancer theranotics.

Conspectus The development of highly effective medicine requires the on-time monitoring of the medical treatment process. This combination of monitoring and therapeutics allows a large degree of control on the treatment efficacy and is now commonly referred to as “theranostics”. Magnetic nanoparticles (NPs) provide a unique nano-platform for theranostic applications due to their comparable sizes with various functional biomolecules, their biocompatibility and their responses to the external magnetic field. Recent efforts in studying magnetic NPs for both imaging and therapeutic applications have led to great advances in NP fabrication with controls in dimension, surface functionalization and magnetic property. These magnetic NPs have been proven to be robust agents that can be target-specific for enhancing magnetic resonance imaging sensitivity and magnetic heating efficiency. These, plus the deep tissue penetration of magnetic field, make magnetic NPs the most promising candidates for successful theranostics in the future. In this Account, we review the recent advances in the synthesis of magnetic NPs of iron oxide, Fe, as well as FePt and FeCo NPs for imaging and therapeutic applications. We will first introduce briefly nanomagnetism, magnetic resonance imaging (MRI), and magnetic fluid hyperthermia (MFH). We will then focus on chemical synthesis of monodisperse magnetic NPs with controlled sizes, morphologies, and magnetic properties. Typical examples in using monodisperse magnetic NPs for MRI and MFH are highlighted.