NIR-II fluorescent Ag2Se polystyrene beads in a lateral flow immunoassay to detect biomarkers for breast cancer.

Fluorescent lateral flow immunoassay (LFA), one tool in point of care testing (POCT) systems for breast cancer, has attracted attention because it is quick, simple, and convenient. However, samples and the constituent material exhibit autofluorescence in the visible region, which is a very large obstacle in the development of fluorescent LFAs. The autofluorescence of biological samples is scarcely found in the second near-infrared (NIR-II) range and samples scatter and absorb less NIR-II light than visible light. Here, we report an NIR-II QD-LFA platform using the NIR-II fluorescent Ag2Se quantum dots (QDs) with 1020 nm emission encapsulated into polystyrene beads as fluorescent probes. The NIR-II LFA platform was established to detect breast cancer tumour markers (CEA and CA153) within 15 min with a low limit of detection (CEA: 0.768 ng mL-1, CA153: 1.192 U mL-1), high recoveries (93.7% ~ 108.8%), and relative standard deviations (RSDs) of less than 10%. This study demonstrated the potential of NIR-II Ag2Se polystyrene beads as a fluorescent probe in LFA for rapid and accurate identification of biomarkers. They are suited for use in professional situations.

Cathodic electrodeposited Cu-BTC MOFs assembled from Cu(II) and trimesic acid for electrochemical determination of bisphenol A.

The authors describe a novel electrochemical determination method for bisphenol A (BPA) based on the electrosynthesised Cu-BTC (H3BTC: trimesic acid) films. Using H3BTC as the ligand, Cu(NO3)2 as the precursor of copper ions, and triethylamine hydrochloride (Et3NHCl) as the probase source, Cu-BTC films were directly deposited on glassy carbon electrode (GCE) surface via cathodic electrochemical reduction under -1.30 V. Considering the electrocatalytic activity of metal center Cu2+, Cu-BTC films were applied to construct the electrochemical determination platform for BPA. Chronocoulometry and electrochemical impedance spectroscopy were used to study the signal enhancement mechanism. The determination conditions were optimized. As a result, a sensitive electrochemical method was constructed for BPA. The peak currents, best measured at voltage of 0.496 V vs. SCE (KCl saturated calomel reference electrode), increase linearly in the range from 5.0 to 2000 nM. The value of determination limit is 0.72 nM. The proposed method was successfully applied to determine BPA in spiked urine, spiked waste water samples and plastic products. The results were in good agreement with those obtained for the same samples by high-performance liquid chromatography (HPLC). Graphical abstract Schematics for the construction of electrochemical determination for bisphenol A.

Dual-template magnetic molecularly imprinted polymers for selective extraction and sensitive detection of aflatoxin B1 and benzo(α)pyrene in environmental water and edible oil.

The coexistence of multiple contaminates in the environment and food is of growing concern due to their extremely hazard as a well-known class I carcinogen, like aflatoxin B1 (AFB1) and benzo(α)pyrene (BaP). AFB1 and BaP are susceptible to coexistence in environmental water and edible oil, posing a significant potential risk to environmental monitoring and food safety. The remaining challenges in detecting multiple contaminates include unsatisfied sensitivity, insufficient targets selectivity, and interferences in complex matrices. Here, we developed dual-template magnetic molecularly imprinted polymers (DMMIPs) for selective extraction of dual targets in complex matrices from the environment and food. The DMMIPs were fabricated by surface imprinting with vinyl-functionalized Fe3O4 as carrier, 5,7-dimethoxycoumarin and pyrene as dummy templates, and methacrylamide as functional monomer. The DMMIPs showed excellent adsorption ability (12.73-15.80 mg/g), imprinting factors (2.01-2.58), and reusability of three adsorption-desorption cycles for AFB1 and BaP. The adsorption mechanism including hydrogen bond, electrostatic interaction and van der Waals force was confirmed by physical characterization and DFT calculation. Applying DMMIPs in magnetic solid phase extraction (MSPE) followed by high-performance liquid chromatography (HPLC) analysis enabled detection limits of 0.134 µg/L for AFB1 and 0.107 µg/L for BaP. Recovery rates for water and edible oil samples were recorded as 86.2%-110.3% with RSDs of 4.1%-11.9%. This approach demonstrates potential for simultaneous identification and extraction of multiple contaminants in environmental and food.

Efficient Antimicrobial Effect of Alginate-Catechol/Fe2+ Coating on Hydroxyapatite toward Oral Care Application.

Reducing the formation of oral bacterial biofilms is critical to prevent common dental diseases. Though many strategies for restricting bacterial adhesion on tooth surfaces have been reported, a simple method for efficient oral bacteriostasis is still highly expected. Herein, we have proved a soft gel made of an alginate-catechol conjugate (SA-DA) and the ferrous cation (Fe2+) as an effective antibacterial coating on hydroxyapatite (HAP, a tooth model). As suggested by quartz crystal microbalance (QCM) measurements, SA-DA/Fe2+ coating possessed a high binding affinity to HAP without destruction by either immersion in artificial saliva or simulated tooth brushing. Significantly less protein (bovine serum albumin) and Streptococcus mutans (S. mutans, an oral bacterial model) could be found on HAP after coating with SA-DA/Fe2+, indicating that the prepared gel could resist well the adhesion of biofouling and microbes due to its hydrophilicity. Notably, such an antibacterial effect (around 70% S. mutans was inhibited) could be maintained for 3 d, which resulted from the extremely good stability of SA-DA/Fe2+ coating, as confirmed by QCM analysis. Our results may offer possibilities for developing applications in order to further improve oral hygiene.

A Surface-Confined Gradient Conductive Network Strategy for Transparent Strain Sensors toward Full-Range Monitoring.

The development of transparent and flexible sensors suitable for the full-range monitoring of human activities is highly desirable, yet presents a daunting challenge due to the need for a combination of properties such as high stretchability, high sensitivity, and good linearity. Gradient structures are commonly found in many biological systems and exhibit excellent mechanical properties. Here, we report a novel surface-confined gradient conductive network (SGN) strategy to construct conductive polymer hydrogel-based stain sensors (CHSS). This CHSS showed an ultrahigh stretchability of 4000% strain, transparency above 90% at a wavelength of 600 nm, as well as skin-like Young's modulus of 40 kPa. Impressively, the sensitivity was improved to 3.0 and outstanding linear sensing performance was achieved simultaneously in the ultrawide range of 0% to 4000% strain with a high R-square value of 0.994. With the help of SGN strategy, this CHSS was able to monitor both large-scale and small-scale human motions and activities. This SGN strategy can open a new avenue for the development of novel flexible strain sensors with excellent mechanical, transparent, and sensing performance for full-range monitoring of human activities.

[Optimal sequence algorithm of divided period appointment consultation service sequence for re-visiting patients in the department of stomatology].

PURPOSE: An optimal sequence algorithm model of divided period appointment consultation service was built through optimal sequence algorithm. METHODS: Re-visiting patients in the department of stomatology in a tertiary hospital were enrolled as the research objects in this study. Information about the diagnose term of common diseases, tooth positions treated, doctor's consultation hours were collected. After calculating the mean consultation hours of each disease based on the statistical analysis, the appointment consultation service sequence of re-visiting patients in the department of stomatology was optimized in accordance with the rule of "providing priority service to those requiring short consultation hours" by referencing to the theoretical model of parallel machine. RESULTS: The total waiting hours of patients after optimizing the appointment consultation sequence was decreased by 35.1%. CONCLUSIONS: Optimal sequence algorithm can optimize divided period consultation sequence, effectively shorten waiting hours and improve patients' medical experience.

Preparation of CMC-modified melamine resin spherical nano-phase change energy storage materials.

A novel carboxymethyl cellulose (CMC)-modified melamine-formaldehyde (MF) phase change capsule with excellent encapsulation was prepared by in situ polymerization. Effects of CMC on the properties of the capsules were studied by Fourier transformation infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electronic microscopy (SEM), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). The results showed that the CMC-modified capsules had an average diameter of about 50nm and good uniformity. The phase change enthalpy of the capsules was increased and the cracking ratio decreased by incorporating a suitable amount of CMC. The optimum phase change enthalpy of the nanocapsules was 83.46J/g, and their paraffin content was 63.1%. The heat resistance of the capsule shells decreased after CMC modification. In addition, the nanocapsule cracking ratio of the nanocapsules was 11.0%, which is highly attractive for their application as nano phase change materials.