Lateral-flow assays (LFAs), with its convenience and low cost, promise to become the in-home test format for early diagnosis and monitoring of tumor marker. However, the insufficient signal intensity was generated by signal reporters reducing the sensitivity of this format. In this study, a novel nanoscale signal reporter capable of amplifying the fluorescence signal is fabricated by encapsulating quantum dots (QDs) into modified tri-copolymer (poly(tert-butyl acrylate-co-ethyl acrylate-co-methacrylic acid)) (ODA-g-tri-copolymer). The amplified signal varied by simply adjusting the ratio of QDs to the ODA-g-tri-copolymer for obtaining QD nanospheres with high QD loading. They exhibits outstanding stability compared to the individual QDs both in the biological buffer and strong acid solutions. Here, human chorionic gonadotrophin (HCG) is employed as the model protein of LFAs. The results show that the detection limit of the QD nanospheres is pushed down to 0.016 IU/L, which is about ~?38.5 times enhanced compared to the individual QD-based LFAs without any signal amplifying. The ultrasensitive LFAs were attributed to the signal amplification strategy, and their efficiency and robustness demonstrated the great potential in clinical applications.
In order to well study the influence of the thickness and doping concentration on optical properties of transmission-mode GaAs photocathode, three exponential-doping and one uniform-doping photocathode modules were prepared by molecular beam epitaxy with a structure of glass/Si3N4/Ga1 ? xAlxAs/GaAs. By use of the spectrophotometer, the optical properties were separately measured including the reflectivity and transmissivity curves. Based on thin film optical principles, the optical properties and their integral values are calculated by matrix formula for the four-layer photocathode module. The result shows that the antireflection and window layers affect the peak and valley of the optical property curves and the active layer influences the absorptivity values of the transmission-mode cathode modules. The photocathode module has high absorptivity within the response waveband when the optimal module has the Si3N4 antireflection layer of 0.1 μm, the Ga1 ? xAlxAs window layer of more than 0.4 μm, and the GaAs active layer of 1.5 μm–2 μm and low average doping concentration. 相似文献
In the glasses coloured with Cd (S, Se, Te), the dependence of the absorption coefficient () on photon energy (E) and temperature (T) has been determined. Some results that differ from the Urbach rule were obtained. 相似文献
Through tuning the surface wettability of interfacially active TiO2 particles, a pH-responsive Pickering emulsion system is formed, as in situ separation and recycling of the nano-catalysts system. 相似文献
Nitrogen‐enriched porous nanocarbon, graphene, and conductive polymers attract increasing attention for application in supercapacitors. However, electrode materials with a large specific surface area (SSA) and a high nitrogen doping concentration, which is needed for excellent supercapacitors, has not been achieved thus far. Herein, we developed a class of tetracyanoquinodimethane‐derived conductive microporous covalent triazine‐based frameworks (TCNQ‐CTFs) with both high nitrogen content (>8 %) and large SSA (>3600 m2 g?1). These CTFs exhibited excellent specific capacitances with the highest value exceeding 380 F g?1, considerable energy density of 42.8 Wh kg?1, and remarkable cycling stability without any capacitance degradation after 10 000 cycles. This class of CTFs should hold a great potential as high‐performance electrode material for electrochemical energy‐storage systems. 相似文献
To deal with the large volume change for lithium-ion batteries (LIBs), we illustrate the synthesis of CoMn2O4 microspheres with sub-nanoparticles by a hydrothermal method followed by thermal treatment. The size of microsphere is approximately 2.2 μm, and the sub-nanoparticle is about 17 nm. There is sufficient void space between CoMn2O4 microspheres with sub-nanoparticles for ensuring the well structural integrity. As advanced anode for LIBs, CoMn2O4 microspheres display stable specific capacity retention of 772 mAh g?1 over 500 cycles at a current density of 100 mA g?1. Such a kind of structure is beneficial for enhanced rate and cycling capabilities in LIBs applications, which could increase contact area between electrolyte and active materials, short path for lithium ions and electrons and accommodate the volume change with additional void space during cycling. It has a great application prospect for use as electrochemical energy storage because of the enhanced performance. 相似文献
A series of partially fluorinated cationic gemini surfactants and their corresponding monomeric surfactants have been studied by isothermal titration microcalorimetry. The critical micelle concentration (CMC) and enthalpy of micellization (DeltaH(mic)) were obtained from calorimetric curves. The CMCs of the gemini surfactants are much lower than those of the corresponding monomeric surfactants and decrease with an increase in the number of fluorine atoms on the hydrophobic chain. The micellization of partially fluorinated cationic gemini surfactants is much more exothermic than that of the corresponding monomeric surfactants. Because of the incompatibility of hydrocarbon spacer and partially fluorinated chain, DeltaH(mic) values of the surfactants with a C6 spacer are more negative than those of the surfactants with a C12 spacer. The variations in the architecture of the fluorocarbon chain segments may be the reason of the irregularities in the change of DeltaH(mic) for the gemini surfactants. Moreover, the contribution of the enthalpy generally increases with an increase in the number of fluorine atoms. 相似文献