A dual-channel visual sensing system for recognition of multiple metal ions.

Here, we propose a simple, rapid, and effective colorimetric sensor array for discrimination of metal ions. The sensor array was constructed using two sensing channels, i.e., gold nanoparticles (AuNPs)- Tetramethylbenzidine (TMB)-H2O2 and AuNPs-O-phenylenediamine (OPD)-H2O2 reaction systems. The presence of metal ions with positive charges would lead to the corresponding surface charge change of negatively charged AuNPs, resulting in diverse catalytic performances of citrate-modified AuNPs, accompanied by a substantial colorimetric performance of oxidation products of TMB and OPD. Employing the diversity of colorimetric responses of metal ions to the two sensing channels, nine metal ions including Cr3+, Fe3+, Cu2+, Co2+, Ni2+, Pb2+, Mg2+, K+, and Cd2+ were well distinguished with a discrimination accuracy of 100% at a concentration as low as 50 nM. Further experiment showed that the sensor array was also capable of discriminating and quantifying metal ions at various concentrations, as well as the identification of metal ion mixtures. The feasibility of the sensor array was also verified by the successful identification of the nine metal ions in river water samples.

A colorimetric sensing probe for chromium (III) ion based on domino like reaction.

In this work, a gold nanobipyramid@Ag nanorod (AuNBP@Ag NR)-based sensor platform was developed for the quantitative, visual, and sensitive detection of Cr3+ ions in aqueous solutions. This assay provides quantitative detection of Cr3+, which relies on the absorbance change of AuNBP@Ag NRs due to morphological change of the AuNBP@Ag NRs induced by Cr3+. When AuNBP@Ag NRs and Cr3+ mix, the coordination reaction of the carboxyl groups of citrate and Cr3+ occurs, which leads to the collapse of Ag shell nanorods, similar to the domino effect, and obvious color changes from yellow to pink can be observed by the naked eye. When combined with UV-vis spectrophotometer-based colorimetric detection, a detection limit of 8.7 nM for Cr3+ in ultrapure water was achieved. With the advantages of high sensitivity, selectivity, and performance, we anticipate that the sensor will be helpful for the on-site, quantitative detection of Cr3+ ions in water samples.

The effect of acupuncture on the expression of inflammatory factors TNF-α, IL-6,IL-1 and CRP in cerebral infarction: A protocol of systematic review and meta-analysis.

BACKGROUND: The mechanisms of acupuncture on the treatment of cerebral infarction remain unclear, the aim of the present study was to provides a protocol of systematic review and meta-analysis, with which we will collect clinical evidence to verify whether acupuncture will have an effect on reducing the levels of tumor necrosis factor α (TNF-α), C-reactive protein (CRP), interleukin-1 (IL-1), and interleukin (IL-6) after cerebral infarction based on evidence-based studies. METHODS: Included studies will be retrieved according to inclusion and exclusion criteria from 5 English databases (the MEDLINE via PubMed, the Cochrane Library, Embase, the Web of Science, and Ovid database), and 4 Chinese databases (China Science and Technology Journal Database (VIP), Chinese Biomedical Literature Database (CBM), Wan-fang Database, China National Knowledge Infrastructure (CNKI)) from October 1990 to October 2017. The inflammatory factor levels of TNF-α and IL-1,IL-6,CRP will be marked as major outcomes. We will use RevMan V.5.3 software to calculate the data synthesis and will conduct meta-analysis based on the collected data. RESULTS: The inflammatory factor levels of TNF-α and IL-1,IL-6,CRP, mortality and adverse effects will be measured and comprehensively assessed to evaluate the adjunctive effect of XBP on CHF from this systematic review and meta-analysis with current clinical evidence. CONCLUSION: The systematic review and meta-analysis will assess the effect of acupuncture on the expression of inflammatory factors TNF-α, IL-6, IL-1 and CRP in cerebral infarction with up-to-date clinical evidence. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42017078583.