No abstract

This study demonstrated a L-glutathione-modified nonadiabatic microfiber sensor to detect a trace level of heavy metal ions in aqueous solution. The sensor showed an exclusively selective response to Pb 2+ among other metal ions and a measured detection limit of 5 μg/L, lower than the maximum allowable limit of Pb 2+ in drinking water by the World Health Organization. Moreover, a novel compact all-fiber-based interrogation scheme was proposed to promote the development of a portable hand-held system for on-site measurement. The presented scheme does not require costly and bulky laboratory equipment but operates based on the reflected optical power of two fiber Bragg gratings (FBG), measured using photodetectors independently.

The application of a pH-tuning concept to create specific analytical responses of carbon dots towards a specific targeted metal ion.

Cancer is one of the leading causes of death. Despite the huge progress in the field of cancer drugs and therapies, the treatment outcome is still bleak for most cancer patients. Nanotechnology has revolutionized cancer therapeutics. By using nano-sized particles as delivery systems, therapeutic biomolecules are transported efficiently to the target sites. Moreover, these particles are designed to carry out multiple cancer treatments simultaneously. Near-infrared (NIR) light-responsive nanomaterials have gained much attention as NIR light has a greater penetration depth, minimal phototoxicity, lower autofluorescence, and reduced light scattering. Among the available NIR light-responsive nanomaterials, gold nanorods, upconversion nanoparticles, carbon dots, transition metal dichalcogenide, metal oxides, black phosphorus, and polymeric nanomaterials have become attractive options owing to their excellent optical properties, ease of synthesis and modification, outstanding photodynamic and photothermal conversion properties, and most importantly, favorable toxicity level and biocompatibility which are prerequisites for biological applications. In this review, the outstanding properties, synthesis, and surface functionalization of the aforementioned NIR light-responsive nanomaterials are introduced in detail. Recent advances of these nanomaterials for various cancer treatment modalities are summarized to highlight their versatility and potential in cancer theranostics. Finally, a perspective is proposed on future research directions and their clinical translation.

Near‐infrared (NIR) light responsive materials have received much attention for diverse applications due to their excellent optical properties. This type of material exhibits upconverted luminescence, a non‐linear optical process in which two or more low energy photons, usually from NIR light irradiation are transformed to high energy photons emission through energy transfer upconversion, excited state absorption, photon avalanche or multiphoton absorption. The NIR range of excitation source is favorable for biological imaging and cancer theranostic applications due to their high penetration depth, low autofluorescence, minimal light scattering, reduced photodamage, and negligible phototoxicity. Having these properties, NIR responsive materials such as upconversion nanoparticles (UCNPs) and carbon dots (CDs) which perform upconversion luminescence are actively exploited in a wide variety of applications such as display and sensory technology. While CDs are well known for their versatility in using different chemicals and green precursors to achieve tunable optical properties, UCNPs also have the advantage that a continuous‐wave NIR laser can be used as the excitation source. This article reviews the properties of these two materials in the aspects of luminescence mechanisms and their recent developments in cancer theranostics, display technology, biosensing and metal ions sensing applications. © 2018 Society of Chemical Industry

No abstract

Herein, we employ a galvanic replacement approach to create atomically dispersed Au on degradable zero-valent Cu nanocubes for tumor treatments on female mice. Controlling the addition of precursor HAuCl4 allows for the fabrication of different atomic ratios of AuxCuy. X-ray absorption near edge spectra indicates that Au and Cu are the predominant oxidation states of zero valence. This suggests that the charges of Au and Cu remain unchanged after galvanic replacement. Specifically, Au0.02Cu0.98 composition reveals the enhanced •OH generation following O2 → H2O2 → •OH. The degradable Au0.02Cu0.98 released Cu+ and Cu2+ resulting in oxygen reduction and Fenton-like reactions. Simulation studies indicate that Au single atoms boot zero-valent copper to reveal the catalytic capability of Au0.02Cu0.98 for O2 → H2O2 → •OH as well. Instead of using endogenous H2O2, H2O2 can be sourced from the O2 in the air through the use of nanocubes. Notably, the Au0.02Cu0.98 structure is degradable and renal-clearable.

Two-dimensional (2D) transition-metal dichalcogenides such as molybdenum disulfide (MoS2) have received a great deal of attention for high-performance gas sensing applications. Unfortunately, before their translation to commercial use, several scientific problems remain to be solved. The challenges include poor stability in a humid environment, random deposition manner of MoS2 flakes that makes the process unscalable, and incomplete recovery at room temperature. Herein, we report a strategy for the room-temperature volatile organic compound (VOC) sensor using the optical microfiber sensing technology. We demonstrated well-controlled immobilization of MoS2 nanosheets onto the optical sensing region using the optical deposition technique. The experimental results show that the MoS2-functionalized optical microfiber sensor achieves high selectivity to polar aprotic and nonpolar VOCs. The sensor demonstrated high sensitivity of 0.0195, 0.0143, 0.0072, and 0.0058 nm/ppm to acetone, ethyl acetate, cyclohexane, and IPA, respectively. Finally, the repeatability and complete recovery capabilities of the sensor have also been validated in this work.