Selenide and telluride glasses for mid-infrared bio-sensing

Abstract

Fiber Evanescent Wave Spectroscopy (FEWS) is an efficient way to collect optical spectra in situ, in real time and even, hopefully, in vivo. Thanks to selenide glass fibers, it is possible to get such spectra over the whole mid-infrared range from 2 to 12 µm. This working window gives access to the fundamental vibration band of most of biological molecules. Moreover selenide glasses are stable and easy to handle, and it is possible to shape the fiber and create a tapered sensing head to drastically increase the sensitivity. Within the past decades, numerous multi-disciplinary studies have been conducted in collaboration with the City Hospital of Rennes. Clinical trials have provided very promising results in biology and medicine which have led to the creation in 2011 of the DIAFIR Company dedicated to the commercialization of fiber-based infrared biosensors. In addition, new glasses based on tellurium only have been recently developed, initially in the framework of the Darwin mission led by the European Space Agency (ESA). These glasses transmit light further into the far-infrared and could also be very useful for medical applications in the near future. Indeed, they permit to reach the vibrational bands of biomolecules laying from 12 to 16 µm where selenide glasses do not transmit light anymore. However, while Se is a very good glass former, telluride glasses tend to crystallize easily due to the metallic nature of Te bonds. Hence, further work is under way to stabilize the glass composition for fibers drawing and to lower the optical losses for improving their sensitivity as bio-sensors.

Free‐volume structure of polyvinylpyrrolidone‐capped glassy As2Se3 nanocomposites prepared by mechanical milling

“…The studied nanocomposites were prepared using coarse‐grained pieces of bulk g‐As 2 Se 3 synthesized by melt quenching from high‐purity commercial elemental precursors (As and Se of 5 N purity) as described in more details elsewhere . The plane‐parallel plates (1.0–1.5 mm in a thickness) cut from glassy ingots and polished were used as reference samples for input characterization and PAL spectroscopy measurement.…”

“…In a majority of different medicinal implementations, the mechanically milled (MM) arsenicals are often combined with organic stabilizers such as polyvinylpyrrolidone (PVP), to keep the individuality of the created nanoparticles (NPs), thereby producing the PVP‐capped arsenical nanocomposites . To the best of our knowledge, there are no comparative information concerning similar functionalization in other arsenicals, such as binary arsenic selenides As‐Se, forming a large group of archetypal glassy‐like media possessing widespread application in optoelectronics, IR photonics, optotelecommunication, and chemical sensing .…”

Nanoscale mechanism of rare‐earth doping in Ga‐codoped glassy As‐Sb selenides

“…With respect to eventual using of RE‐doped ChG in fiber optics, the thermal behavior of each sample was examined using differential scanning calorimetry (DSC) with TA Instruments Q20 (TA Instruments, Inc., New Castle, DE, USA). Typically, 10‐mg bulk samples were sealed in standard aluminum pans and heated at 10°C/min heating rate.…”

“…Rare-earth (RE)-doped chalcogenide glasses (ChG) attract great attention in modern materials science community as versatile device media for a variety of active applications in mid-IR optics including fiber-optics amplifiers and IR lasers. [1][2][3] However, this sphere of chalcogenide photonics has still being highly disputable now because of insufficient knowledge on the nature of RE-activated functionality in covalent-saturated ChG networks.…”

Devitrification of Bi- and Ga-containing germanium-based chalcogenide glasses

“…Conventionally, this goal is achieved through the variation in composition of complex ChG, which allows tailoring their physical properties to match the requirements. As a result of such approach, number of complex Te-and Se-based compositions are proposed for application in far-IR optics, waveguiding for space telecommunication, optical and bio-sensing technologies, phase-change memory devices [1][2][3][4][5][6]. However, significant enhancement of ChG initial properties is also possible due to design on the nanoscale.…”