9 research outputs found
Highly Sensitive Detection of Naphthalene in Solvent Vapor Using a Functionalized PBG Refractive Index Sensor
We report an optical refractive index sensor system based on a planar Bragg grating which is functionalized by substituted γ-cyclodextrin to determine low concentrations of naphthalene in solvent vapor. The sensor system exhibits a quasi-instantaneous shift of the Bragg wavelength and is therefore capable for online detection. The overall shift of the Bragg wavelength reveals a linear relationship to the analyte concentration with a gradient of 12.5 ± 1.5 pm/ppm. Due to the spectral resolution and repeatability of the interrogation system, this corresponds to acquisition steps of 80 ppb. Taking into account the experimentally detected signal noise a minimum detection limit of 0.48 ± 0.05 ppm is deduced
Trace detection of explosives by microring resonators
A silicon microring resonator coated with specifically synthesized receptor molecules that enables the sensitive and selective detection of trinitrotoluene in the gas phase is presented
Sensitized silicon ring resonators for the detection of TNT in the gas phase
A silicon ring resonator is coated with receptor molecules for selective enrichment of TNT. Upon intercalation of TNT, changes in effective refractive index lead to a shift in resonance frequency which can accurately be determined
Graphene oxide integrated silicon photonics for detection of vapour phase volatile organic compounds
Cytokines: From Clinical Significance to Quantification
Abstract Cytokines are critical mediators that oversee and regulate immune and inflammatory responses via complex networks and serve as biomarkers for many diseases. Quantification of cytokines has significant value in both clinical medicine and biology as the levels provide insights into physiological and pathological processes and can be used to aid diagnosis and treatment. Cytokines and their clinical significance are introduced from the perspective of their proâ and antiâinflammatory effects. Factors affecting cytokines quantification in biological fluids, native levels in different body fluids, sample processing and storage conditions, sensitivity to freezeâthaw, and soluble cytokine receptors are discussed. In addition, recent advances in in vitro and in vivo assays, biosensors based on different signal outputs and intracellular to extracellular protein expression are summarized. Various quantification platforms for highâsensitivity and reliable measurement of cytokines in different scenarios are discussed, and commercially available cytokine assays are compared. A discussion of challenges in the development and advancement of technologies for cytokine quantification that aim to achieve realâtime multiplex cytokine analysis for pointâofâcare situations applicable for both biomedical research and clinical practice are discussed