A Paper‐Based Platform for Long‐Term Deposition of Nanoparticles with Exceptional Redispersibility,Stability, and Functionality

Although nanoparticles (NPs) can be carefully engineered to have maximal stability and functionality desirable for use in diverse applications, they are generally not suitable for long‐term storage in solution. It is also difficult to store NPs in a dry state because dried NPs generally become aggregated and cannot easily be redispersed. Thus, a new strategy allowing long‐term storage of NPs with high stability, redispersibility, and functionality is highly demanded. By passivating the 13 nm gold nanoparticle (AuNP) surface with stabilizing agents and treating a paper substrate with both bovine serum albumin and sucrose after coating with a hydrophobic polyvinyl butyral layer, it is possible to fully redisperse (≈100%) dried AuNPs with colloidal stability comparable to that of as‐prepared AuNPs. Furthermore, AuNPs physically stabilized with polyvinylpyrrolidone can react with thiol‐containing compounds, such as 1,4‐dithiothreitol (DTT). Taking advantage of the oxidation reaction of hypochlorous acid with DTT, it is possible to demonstrate a paper‐based colorimetric sensor for detection of residual chlorine in water. Since this strategy is applicable to large‐sized AuNPs (30–90 nm), silver NPs, oleic acid‐capped magnetic NPs, and cetrimonium bromide‐passivated gold nanorods, it can be used for diverse NPs requiring long‐term storage for many applications.     

Simple fabrication of a smart microarray of polystyrene microbeads for immunoassay

We describe a simple method to fabricate an array of polystyrene microbeads (PS μbeads) conjugated with an elastin-like polypeptide (ELP) on a glass surface using a removable polymer template (RPT). A thin layer of adhesive was spun-cast on glass and cured by UV radiation. Micropatterns of an RPT were then transferred onto the surface by microcontact printing. The adhesion of PS μbeads on the surface depended on the adhesion performance of the adhesive layer, which could be adjusted by irradiation time. An array of PS μbeads conjugated with ELP was used for a smart immunoassay of prostate-specific antigen (PSA), a cancer marker. By controlling the phase transition of ELP molecules, PSA molecules were selectively adhered or released from the bead surface. The selective and reversible binding of PSA molecules on the bead surface was characterized with fluorescence microscopy.     

Study of thermal and optical properties of the Ge-Te-CdI2/ZnI2 far infrared transmitting glasses

A systematic series of (100 ? x)(GeTe_4.3) ? xCdI₂/ZnI₂ far infrared transmitting glasses were prepared by traditional melt-quenching method. ZnI₂ (20 mol%) can be introduced in the glassy matrix, while only 10 mol% CdI₂ can be incorporated in the Ge-Te-CdI₂ glass system. Based on differential thermal analysis (DTA) data, most of the glass samples have good thermal stability. A maximum ΔT value of 115 °C was obtained for the glass composition 90(GeTe_4.3)–10ZnI₂. The allowed indirect transition optical band gap was calculated according to the classical Tauc equation. It is found that the indirect optical band gap decreased from 0.619 to 0.569 eV with the CdI₂ addition and increased from 0.628 to 0.677 eV with the ZnI₂ addition. According to infrared transmission spectra, the Ge-Te-CdI₂/ZnI₂ glasses show wide IR transparency.     

Endpoint estimates for some maximal operators associated to the circular conical surface

For and m>0 we consider the maximal operator given by

     

Fabrication of one-dimensional colloidal assemblies from electrospun nanofibers

Electrospun nanofibers were used as confining geometries for fabricating 1-D colloidal assemblies. Silica particles dispersed in several different polymer solutions were cast into nanofibers by an electrospinning process. The silica particle configurations were examined in terms of the size ratio of silica particles to nanofibers and the properties of the dispersing medium. As the electrospun fiber was extended highly, the silica particles dispersed in the polymer solution began to assemble spontaneously into a pearl-necklace structure. We also demonstrated the alignment of 1-D silica assemblies using a designed configuration of collector electrodes.     

Bidirectional transfer of quantum information for unknown photons via cross-Kerr nonlinearity and photon-number-resolving measurement

We propose an arbitrary controlled-unitary(CU) gate and a bidirectional transfer scheme of quantum information(BTQI) for unknown photons.The proposed CU gate utilizes quantum non-demolition photon-number-resolving measurement based on the weak cross-Kerr nonlinearities(XKNLs) and two quantum bus beams;the proposed CU gate consists of consecutive operations of a controlled-path gate and a gathering-path gate.It is almost deterministic and is feasible with current technology when a strong amplitude of the coherent state and weak XKNLs are employed.Compared with the existing optical multi-qubit or controlled gates,which utilize XKNLs and homodyne detectors,the proposed CU gate can increase experimental realization feasibility and enhance robustness against decoherence.According to the CU gate,we present a BTQI scheme in which the two unknown states of photons between two parties(Alice and Bob) are mutually swapped by transferring only a single photon.Consequently,by using the proposed CU gate,it is possible to experimentally implement the BTQI scheme with a certain probability of success.     

Comment on “Quantum Signature Scheme with Weak Arbitrator”

This comment explains that the quantum signature scheme proposed by Ming-Xing Luo et al. (in Int. J. Theor. Phys. 51:2134, 2012) cannot satisfy the signature requirements. The comment presents methods of possible attacks by forgers, while also demonstrating that it is difficult to proceed by the normal protocol because of some errors in the formula of the scheme.     

Self-deprotonation and colorization of 1,3-bis(dicyanomethylidene)indan in polar media: a facile route to a minimal polymethine dye for NIR fluorescence imaging

Colorless 1,3-bis(dicyanomethylidene)indan is an organic acid (pK(a) ≈3.0) that turns blue in polar media owing to self-deprotonation. Moreover, its colored conjugate base shows potential as a minimal anionic polymethine dye for probing biomolecules in cells and in vivo through noncovalent complexation and near-infrared fluorescence signaling.