Accurate in vivo tumor detection using plasmonic-enhanced shifted-excitation Raman difference spectroscopy (SERDS)

For the majority of cancer patients, surgery is the primary method of treatment. In these cases, accurately removing the entire tumor without harming surrounding tissue is critical; however, due to the lack of intraoperative imaging techniques, surgeons rely on visual and physical inspection to identify tumors. Surface-enhanced Raman scattering (SERS) is emerging as a non-invasive optical alternative for intraoperative tumor identification, with high accuracy and stability. However, Raman detection requires dark rooms to work, which is not consistent with surgical settings. Methods: Herein, we used SERS nanoprobes combined with shifted-excitation Raman difference spectroscopy (SERDS) detection, to accurately detect tumors in xenograft murine model. Results: We demonstrate for the first time the use of SERDS for in vivo tumor detection in a murine model under ambient light conditions. We compare traditional Raman detection with SERDS, showing that our method can improve sensitivity and accuracy for this task. Conclusion: Our results show that this method can be used to improve the accuracy and robustness of in vivo Raman/SERS biomedical application, aiding the process of clinical translation of these technologies. © The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/). See http://ivyspring.com/terms for full terms and conditions

Spectroscopic Chemical Sensing and Imaging: From Plants to Animals and Humans

Chemical sensing and imaging technologies are of great importance in medical diagnostics and environmental sensing due to their ability to detect and localize chemical targets and provide valuable information in real-time. Biophotonic techniques are the most promising for in vivo applications due to their minimal invasivity. Our laboratory has introduced various biophotonics-based technologies for chemical sensing and imaging for biochemical sensing, medical diagnostics, and fundamental research. Over the years, we have developed a wide variety of fluorescence and surface-enhanced Raman scattering (SERS)-based technologies for the detection of biomarkers for cancer and other diseases. This paper provides an overview of the research on chemical and biological sensors developed in our laboratory, highlighting our work on in vivo imaging and sensing, including minimally invasive detection of endogenous fluorophores associated with malignant tissue, SERS-tag localization of cancer cells and tissues, and SERS-based detection of nucleic acid biotargets and its feasibility for in vivo applications. This manuscript also presents new development on the use of Raman imaging of SERS-labeled nanoprobes incubated in leaves for use in biofuel research, laying the foundation for studies on functional imaging of nucleic acid biomarkers in plants

Encapsulating carbon nanotubes in aqueous ds-DNA anisotropic phases: shear orientation and rheological properties

Carbon nanotubes reinforce polymer composites providing nanotube-based nanohybrids with potentially outstanding properties. The dispersion quality, however, influences the performances of the resulting materials. Therefore, new preparation procedures and efficient dispersion strategies are needed. A new method encapsulating single-walled carbon nanotubes in a nematic phase of double stranded DNA-water-NaCl is reported here. The procedure relies on osmotic compression and on its role in compacting DNA-nanotube composites. An anionic polymer (sodium dextransulfate) was added to the above dispersions and segregative phase separation was induced. DNA-nanotube composites were concentrated and phase-separated from the coexisting polymer solution. In this way, high concentrations of carbon nanotubes can be incorporated in the DNA-rich phase, inducing a transition from liquid- to solid-like behavior. The resulting nematic fluids are homogeneous and orient when shear stresses are applied. The kinetics of re-alignment was determined by rheological and spectroscopic methods. The effect of the nanotubes on the resulting behavior was accounted for. A slowing down of DNA motion observed in such composite matrices suggests interactions with nanotubes

Evolution of Raman Spectroscopy for Cultural Heritage: advanced prototypes

The technological evolution of Raman Spectroscopy for increasingly effective applications in Cultural Heritage field is the topic of the research carried out over the last few years at ISPC Raman Laboratory in collaboration with the Rutherford Appleton Laboratory and the University of Cincinnati [1, 2]. Significant modifications to a commercial micro-Raman instrument led to the development of a benchtop prototype with high lateral and spectral resolution coupled with depth sensitivity and 3D mapping capabilities. Three micro-SORS variants (defocusing, internal beam-steered and point-like) are integrated in the prototype enabling the system to be easily adapted to fit specific applications efficiently. The coupling of micro-SORS with different imaging/mapping modalities (conventional, StreamLine and StreamHR) is paving the way for studies of high-resolution molecular distribution of compounds within volumes in art objects. Moreover, an external horizontal probe permits the non-invasive investigation of large objects too. The in-house portable prototype is designed for a rugged, effective detection of Raman signals both in conventional and spatially offset geometries with high spectral and spatial resolution. This feature is achieved by using a linear fiber bundle to conserve the offset information on the detector, permitting simultaneous acquisition of Raman photons emerging from the surface and subsurface in separate spectra. Different designs and applications to case studies in Cultural Heritage will be presented and discussed

Development of advanced micro-SORS for Heritage Science

The development of two micro-SORS prototypes and their optimization for Heritage Science applications are the result of the research carried out over the last few years at CNR-ISPC Raman Laboratory in collaboration with the Rutherford Appleton Laboratory and the University of Cincinnati [1, 2]. First, a commercial benchtop micro-Raman instrument has been modified for increasing depth sensitivity and 3D mapping capabilities; micro-SORS can be deployed using three different modalities (defocusing, internal beam-steered and point-like) to fit specific application effectively. Painted layer sequences and diffusion of conservation or decay products were investigated using defocusing for obtaining an average distribution of compounds and point-like for increasing the contrast between external and inner portions of the materials; extremely thin layers (10-15 µm) required small spatial offsets provided by internal beam-steered modality. Different imaging/mapping modalities (conventional, StreamLine and StreamHR) were coupled with micro-SORS variants paving the way for studies of high-resolution molecular distribution of compounds hidden by external opaque layers in art objects, as in the case of hidden letters in sealed or closed documents. Secondly, an in-house portable micro-SORS prototype was developed to enable conventional and micro-SORS measurements in situ. This device represents a technological evolution of existing commercial portable Raman since the detection of Raman signals of the surface and subsurface is achieved by using a micrometric linear fiber bundle to conserve the offset information on the detector, permitting simultaneous acquisition of Raman photons emerging from the surface and subsurface in separate spectra in analogy to approaches also used in macro-SORS spectroscopy [3]. The system is particularly well suited to non-invasive analyses in museum collections, archaeological or conservation sites, where vibrations could be an issue, since no additional mechanical movements are required for setting spatial offset. Designs and applications to case studies in Heritage Science will be discussed

Dataset for Next-Generation Nanopore Sensors Based on Conductive Pulse Sensing for Enhanced Detection of Nanoparticles

The data set contains all ion current traces recorded using pClamp system for the associated paper. The data is in the native pClamp format of abf files. The data set is aim to allow users to re-analysis the data and to reproduce the observations made in the associated publication