Monitoring volatile organic compounds (VOCs) is an important issue, but difficult to achieve on a large scale and on the field using conventional analytical methods. Electronic noses (eNs), as promising alternatives, are still compromised by their performances due to the fact that most of them rely on a very limited number of sensors and use databases devoid of kinetic information. To narrow the performance gap between human and electronic noses, we developed a novel optoelectronic nose, which features a large sensor microarray that enables multiplexed monitoring of binding events in real-time with a temporal response. For the first time, surface plasmon resonance imaging is demonstrated as a promising novel analytical tool for VOC detection in the gas phase. By combining it with cross-reactive sensor microarrays, the obtained optoelectronic nose shows a remarkably high selectivity, capable of discriminating between homologous VOCs differing by only a single carbon atom. In addition, the optoelectronic nose has good repeatability and stability. Finally, the preliminary assays using VOC binary and ternary mixtures show that it is also very efficient for the analysis of more complex samples, opening up the exciting perspective of applying it to "real-world" samples in diverse domains.

We synthesized a generation of water-soluble, atomically precise gold nanoclusters (Au NCs) with anisotropic surface containing short dithiol pegylated chain. These Au NCs exhibit a high brightness (QY∼6%) in the shortwave infrared (SWIR) spectrum with a detection above 1250nm and showed a slow elimination from blood with a weak accumulation in organs. We also developed a non-invasive, whole-body vascular imaging system in the SWIR window with high-resolution, benefiting from a series of Monte Carlo image processing of the images. The imaging process enabled to improve contrast by one order of magnitude and enhance by 54% the spatial resolution. After systemic administration of these nanoprobes in mice, we could quantify vessel complexity in depth (>4mm). Using Bmp9 deficient mice, we can detect very subtle vascular disorders noninvasively. The combination of these anisotropic surface charged gold nanoclusters plus an improved SWIR imaging device allows then a precise mapping at high resolution and in depth of the organization of the vascular network in live animals.

Incorporating anisotropic surface charges on atomically precise gold nanoclusters led to a intense shortwave infrared photoluminescence exceeding 1100 nm with QY up to 6.1%.

Gold nanoclusters (AuNC) have strong potential for cancer imaging and therapy. We demonstrate that optimizing the surface chemistry of AuNCs for increased tumor uptake can significantly affect its potential to augment radiotherapy outcomes.

We evaluated the impact of light-scattering effects on spatial resolution in different SWIR subregions by analyzing two SWIR emissive phantoms made of PDMS-gold nanoclusters (Au NCs) composite covered with mice skin, or capillary tubes filled with Au NCs or IRDye 800CW at different depth in intralipids and finally, after administration of the Au NCs intravenously in mice. Our findings highlighted the benefit of working at the highest tested spectral range of the SWIR region with a 50% enhancement of spatial resolution measured in artificial model when moving from NIR-II (1000-1300 nm) to NIR-IIa (1300-1450 nm) region, and a 25% reduction of the scattering from the skin determined by point spread function analysis from the NIR-II to NIR-IIb region (1500-1700 nm). We also confirmed that a series of Monte Carlo restoration of images significantly improved the spatial resolution in vivo in mice in deep tissues both in the NIR-II and NIR-IIa spectral windows.

The influence of solvent polarity and surface ligand rigidification on the SWIR emission profile of gold nanoclusters with an anistropic surface was investigated. A strong enhancement of the SWIR emission...

We present here a new approach for non-invasive high resolution whole-body vascular imaging in depth by combining water-soluble and bright SWIR-emitting gold nanoclusters revealing an anisotropic surface charge with Monte Carlo image processing of the images. We applied and validated this approach to quantify vessel complexity in transgenic mice presenting vascular disorders.In vivo infrared imaging has experienced major breakthroughs over the past few years with potential applications in cancer and cardio-vascular diagnostics1. Hongjie Dai's team was among the first who developed emitters for the shortwave infrared region (SWIR, 900-1700 nm), also called NIR II. Due to the weak photon absorption, the low autofluorescence, and reduced scattering by tissues at these wavelengths compared to NIR I (700-900 nm) and the

Oligosaccharides derived from λ-carrageenan (λ-COs) are gaining interest in the cancer field. They have been recently reported to regulate heparanase (HPSE) activity, a protumor enzyme involved in cancer cell migration and invasion, making them very promising molecules for new therapeutic applications. However, one of the specific features of commercial λ-carrageenan (λ-CAR) is that they are heterogeneous mixtures of different CAR families, and are named according to the thickening-purpose final-product viscosity which does not reflect the real composition. Consequently, this can limit their use in a clinical applications. To address this issue, six commercial λ-CARs were compared and differences in their physiochemical properties were analyzed and shown. Then, a H2O2-assisted depolymerization was applied to each commercial source, and number- and weight-averaged molar masses (Mn and Mw) and sulfation degree (DS) of the λ-COs produced over time were determined. By adjusting the depolymerization time for each product, almost comparable λ-CO formulations could be obtained in terms of molar masses and DS, which ranged within previously reported values suitable for antitumor properties. However, when the anti-HPSE activity of these new λ-COs was screened, small changes that could not be attributed only to their small length or DS changes between them were found, suggesting a role of other features, such as differences in the initial mixture composition. Further structural MS and NMR analysis revealed qualitative and semi-quantitative differences between the molecular species, especially in the proportion of the anti-HPSE λ-type, other CARs types and adjuvants, and it also showed that H2O2-based hydrolysis induced sugar degradation. Finally, when the effects of λ-COs were assessed in an in vitro migration cell-based model, they seemed more related to the proportion of other CAR types in the formulation than to their λ-type-dependent anti-HPSE activity.