ABSTRACT
Nano coatings for anti-corrosion and electromagnetic wave absorbing can simultaneously implement the functions of assimilating electromagnetic waves and reducing the corrosion of materials caused by corrosive environments, such as seawater. In this work, a composite material for both electromagnetic wave absorption and anti-corrosion was prepared by an in-situ chemical oxidation and surface coating method using carbonyl iron powder (CIP), graphene oxide (GO) and aniline (AN). The synthesized composite material was characterized by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and XRD. The carbonyl iron powder-graphene oxide-polyaniline (CIP-GO-PANI) composite material was used as the functional filler, and the epoxy resin was the matrix body for preparing the anticorrosive wave-absorbing coating. The results show that CIP had strong wave-absorbing properties, and the anti-corrosion property was greatly enhanced after being coated by GO-PANI.
ABSTRACT
Fiber optics evanescent field based biosensor is an excellent candidate for label-free detection of cardiac biomarkers which is of great importance in rapid, early, and accurate diagnosis of acute myocardial infarction (AMI). In this paper, we report a compact and sensitive cardiac troponin I (cTn-I) immunosensor based on the phase-shifted microfiber Bragg grating probe which is functionalized. The fine reflective signal induced by the phase shift in modulation significantly improves the spectral resolution, enabling the ability of the sensor in perceiving an ultra-small refractive index change due to the specific capture of the cTn-I antigens. In buffer, a log-linear sensing range from 0.1 to 10ng/mL and a limit of detection (LOD) of 0.03ng/mL (predicted to be as low as 10.8pg/mL) are obtained. Furthermore, with good specificity, the sensor can be applied in test of cTn-I in human serum samples. The proposed sensor presents superiorities such as improved integratability and portability, easy fabrication and operation, and intrinsic compatibility to the fiber-optic network, and thus has a promising prospect in "point-of-care" test for cardiac biomarkers and preclinical diagnosis.
Subject(s)
Biosensing Techniques/instrumentation , Fiber Optic Technology/instrumentation , Myocardial Infarction/blood , Troponin I/blood , Equipment Design , Humans , Immunoassay/instrumentation , Limit of Detection , Miniaturization , Myocardial Infarction/diagnosis , Optical Fibers , Point-of-Care Systems , RefractometryABSTRACT
In this Letter, Type IIa Bragg gratings are inscribed into microfibers. The large germanium-doped core region of the multimode fiber provides the necessary photosensitivity to form a Type IIa grating when it is drawn down to the microscale. Reducing the diameter of the microfiber due to lower saturate modulation and the amplified tension-strain transformation effect can accelerate the formation of a Type IIa grating. This provides an efficient method for the fabrication of fiber gratings with 800°C temperature resistance.
