Clinical Probe Utilizing Surface-Enhanced Raman Scattering (SERS) for In-Situ Molecular Imaging Applications

In this research, a clinical probe utilizing Surface-Enhanced Raman Scattering (SERS) is developed for molecular imaging application which is a visualizing technology to support early diagnosis by providing images in molecular level. In addition to other molecular imaging applications using magnetic resonance, light, and ultrasound, Raman spectroscopy has great potential in terms of non-invasiveness, safety, imaging agent-free, and scanning multiple molecules at a time. However, the critical limitation of Raman spectroscopy using in-vivo molecular imaging application is the inherent low sensitivity of Raman effect. The challenge is overcome by employing SERS enhancing Raman scattering with concentrated electromagnetic oscillation in nanometallic structures. This phenomenon gives normal Raman spectroscopy more capabilities for diverse applications, especially for a clinical Raman probe of molecular imaging. The imaging apparatus is composed of three parts: SERS substrate with nanostructures, probe with gradient index (GRIN) lens, and signal transmission system from the spectrometer and the probe. For a transparent SERS substrate, electrochemically etched porous silicon (PS) is employed as a master mold from which a transparent UV epoxy is cast, and different thicknesses of gold (Au) are sputtered over the cast nanostructures. Rhodamine 6G solutions on the transparent SERS substrates are characterized and analyzed with various aspects in a fluidic cell. In addition to the transparent SERS substrate, a clinical probe is customized with the optical analysis of gradient-index (GRIN) lens in order to focus laser beam on SERS substrate. A transmission system, called “articulated arm” is built with multiple rotating joints which reflect laser light 90 degree. The clinical probe is assembled with transmission system, and the scanned Raman signals are transmitted from the target specimen to the Raman spectrometer. Some measurement results of a gelatin block contains Rhodamine 6G demonstrate that the developed remote probe using SERS and articulated arm show promising remote Raman detections for molecular imaging applications

Plasma Nanoscience: from Nano-Solids in Plasmas to Nano-Plasmas in Solids

The unique plasma-specific features and physical phenomena in the organization of nanoscale solid-state systems in a broad range of elemental composition, structure, and dimensionality are critically reviewed. These effects lead to the possibility to localize and control energy and matter at nanoscales and to produce self-organized nano-solids with highly unusual and superior properties. A unifying conceptual framework based on the control of production, transport, and self-organization of precursor species is introduced and a variety of plasma-specific non-equilibrium and kinetics-driven phenomena across the many temporal and spatial scales is explained. When the plasma is localized to micrometer and nanometer dimensions, new emergent phenomena arise. The examples range from semiconducting quantum dots and nanowires, chirality control of single-walled carbon nanotubes, ultra-fine manipulation of graphenes, nano-diamond, and organic matter, to nano-plasma effects and nano-plasmas of different states of matter.Comment: This is an essential interdisciplinary reference which can be used by both advanced and early career researchers as well as in undergraduate teaching and postgraduate research trainin

Biomolecular Corona Associated with Nanostructures: The Potentially Disruptive Role of Raman Microscopy

When nanostructures and other materials are exposed to biological fluids, they are immediately covered by a layer of biological molecules, which is typically referred to as a “biomolecular corona” (BC). This represents the first component of a material that interacts with biological systems, so characterizing the composition and the dynamic evolution of BC is essential for predicting the interactions of materials and living organisms. This review provides an analysis of current BC characterization techniques, with particular attention to nanostructures involved in biomedical applications. The influence on cell–nanostructure interactions is assessed and the advantages and limitations of each technique are discussed and compared. An in-depth analysis of Raman microscopy, a relatively unexploited tool with great potential in the characterization of BC, is then conducted. Raman microscopy can be used to analyze a vast amount of specimens without the need for staining, and can provide analysis on a spatial scale of hundreds of nanometers: it may thus represent a potentially disruptive tool for the characterization of BC, as it overcomes many of the limitations posed by current techniques

Biomolecular Corona Associated with Nanostructures: The Potentially Disruptive Role of Raman Microscopy

AbstractWhen nanostructures and other materials are exposed to biological fluids, they are immediately covered by a layer of biological molecules, which is typically referred to as a "biomolecular corona" (BC). This represents the first component of a material that interacts with biological systems, so characterizing the composition and the dynamic evolution of BC is essential for predicting the interactions of materials and living organisms. This review provides an analysis of current BC characterization techniques, with particular attention to nanostructures involved in biomedical applications. The influence on cell–nanostructure interactions is assessed and the advantages and limitations of each technique are discussed and compared. An in‐depth analysis of Raman microscopy, a relatively unexploited tool with great potential in the characterization of BC, is then conducted. Raman microscopy can be used to analyze a vast amount of specimens without the need for staining, and can provide analysis on a spatial scale of hundreds of nanometers: it may thus represent a potentially disruptive tool for the characterization of BC, as it overcomes many of the limitations posed by current techniques

Optically-controlled platforms for transfection and single- and sub-cellular surgery

Improving the resolution of biological research to the single- or sub-cellular level is of critical importance in a wide variety of processes and disease conditions. Most obvious are those linked to aging and cancer, many of which are dependent upon stochastic processes where individual, unpredictable failures or mutations in individual cells can lead to serious downstream conditions across the whole organism. The traditional tools of biochemistry struggle to observe such processes: the vast majority are based upon ensemble approaches analysing the properties of bulk populations, which means that the detail about individual constituents is lost. What are required, then, are tools with the precision and resolution to probe and dissect cells at the single-micron scale: the scale of the individual organelles and structures that control their function. In this review, we highlight the use of highly-focused laser beams to create systems providing precise control and specificity at the single cell or even single micron level. The intense focal points generated can directly interact with cells and cell membranes, which in conjunction with related modalities such as optical trapping provide a broad platform for the development of single and sub-cellular surgery approaches. These highly tuneable tools have demonstrated delivery or removal of material from cells of interest, but can simultaneously excite fluorescent probes for imaging purposes or plasmonic structures for very local heating. We discuss both the history and recent applications of the field, highlighting the key findings and developments over the last 40 years of biophotonics researc

Prospects for plasmonic hot spots in single molecule SERS towards the chemical imaging of live cells

Single molecule surface enhanced Raman scattering (SM-SERS) is a highly local effect occurring at sharp edges,} interparticle junctions and crevices or other geometries with a sharp nanoroughness of plasmonic nanostructures ({"}hot spots{"}). The emission of an individual molecule at SM-SERS conditions depends on the local enhancement field of the hot spots{,} as well as the binding affinity and positioning at a hot spot region. In this regard{,} the stability of near-field nano-optics at hot spots is critical{,} particularly in a biological milieu. In this perspective review{,} we address recent advances in the experimental and theoretical approaches for the successful development of SM-SERS. Significant progress in the understanding of the interaction between the excitation electromagnetic field and the surface plasmon modes at the metallic or metallic/dielectric interface of various curvatures are described. New knowledge on methodological strategies for positioning the analytes for SM-SERS and Raman-assisted SERS or the SERS imaging of live cells has been acquired and displayed. In the framework of the extensive development of SM-SERS as an advancing diagnostic analytical technique{,} the real-time SERS chemical imaging of intracellular compartments and tracing of individual analytes has been achieved. In this context{, we highlight the tremendous potential of SERS chemical imaging as a future prospect in SERS and SM-SERS for the prediction and diagnosis of diseases