Narrow Results

The development of peroxidase mimics with enhanced peroxidase-like activity is critical to building a convenient and fast glucose colorimetric sensor. Herein, a porphyrin-based conjugated microporous polymer (FePCMP) was synthesized through a Pd-/CuI catalyzed Sonogashira coupling reaction. The FePCMP exhibited specific and superior POD-like activity evaluated by the fast oxidation of 3,3$\prime$,5,5$\prime$-tetramethylbenzidine (a chromogenic substrate, TMB) to form the blue product (oxTMB) in the presence of H₂O₂. The outstanding POD-like activity is mainly ascribed to the Fe-N₄ active sites and the cross-linked porous framework of FePCMP. Furthermore, the FePCMP was applied in selective colorimetric detection of glucose through a glucose oxidase biocatalytic cascade reaction with a low detection limit (LOD) of 0.031 $\mu$M in the linear range of 0.2–5 $\mu$M. This study not only provided a new method for the design and synesis of specific POD-like nanozymes, but also the prepared FePCMP can be used as a POD-like enzyme for the colorimetric detection of other molecules, such as cholesterol, acetylcholine, etc.

Er³⁺ and Yb³⁺ co-doped CaBi₂Ta₂O₉ (CBT)-based bismuth layered-structure oxides were synthesized by a simple solid-state reaction method. Their up-conversion (UC) luminescence, dielectric and ferroelectric properties were investigated. Two strong green emission bands centered at 526 and 547 nm and a weak red emission band centered at 658 nm were obtained under a 980 nm laser excitation at room temperature. These emission bands originated from the radiative relaxation of Er³⁺ from ²H_11/2, ⁴S_3/2, and ⁴F_9/2 levels to the ground state ⁴I_15/2, respectively. At the meantime, the fluorescence intensity ratio (FIR) variation of two green UC emissions at 526 and 547 nm has been studied as a function of temperature in the range of 153–603 K. The maximum sensor sensitivity obtained was 39 × 10^-4 K^-1 at 590 K, which indicated that Er³⁺/Yb³⁺ co-doped CBT ceramic is a promising candidate for applications in optical high temperature sensor.

The purpose of this study is to identify and quantify the difference in detections of a subsurface target from a subsurface sensor source between range-independent and range-dependent versions of the same acoustic propagation model. Environmental data were pulled from open source databases to provide an application for the comparison and using novel measures of merit, the authors were able to quantify the difference in detection performance between models. This study suggests that provided multiple types of environments are considered, it is possible to use a range-independent model to give good approximations to the accuracy of detections, one would achieve using a full range-dependent sound propagation model.