A Novel Electrochemical Sensor Modified with a Computer-Simulative Magnetic Ion-Imprinted Membrane for Identification of Uranyl Ion.

In this paper, a novel ion-imprinted electrochemical sensor modified with magnetic nanomaterial FeO@SiO was established for the high sensitivity and selectivity determination of UO in the environment. Density functional theory (DFT) was employed to investigate the interaction between templates and binding ligands to screen out suitable functional binding ligand for the reasonable design of the ion imprinted sensors. The MIIP/MCPE (magnetic ion imprinted membrane/magnetic carbon paste electrode) modified with FeO@SiO exhibited a strong response current and high sensitivity toward uranyl ion comparison with the bare carbon paste electrodes.

Aggregation-induced photoluminescence enhancement of protamine-templated gold nanoclusters for 1-hydroxypyrene detection using 9-hydroxyphenanthrene as a sensitizer.

In this study, we confirmed that protamine-templated gold nanoclusters (PRT-AuNCs) exhibit aggregation-induced emission properties (AIE-PRT-AuNCs). 1-Hydroxypyrene (1-OHPy) further induced the aggregation of AIE-PRT-AuNCs via hydrogen bonding and electrostatic and hydrophobic interactions, resulting in the aggregation-induced photoluminescence enhancement of AIE-PRT-AuNCs. 9-Hydroxyphenanthrene was able to decrease the background signal, thus increasing the sensitivity of the method.

Protamine-gold nanoclusters as peroxidase mimics and the selective enhancement of their activity by mercury ions for highly sensitive colorimetric assay of Hg(II).

We certify that protamine-gold nanoclusters (PRT-AuNCs) synthesized by one-pot method exhibit peroxidase-like activity. The catalytic activity of PRT-AuNCs followed typical Michaelis-Menten kinetics and exhibited higher affinity to 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate compared to that of natural horseradish peroxidase. Meanwhile, we found that Hg(II) could dramatically and selectively enhance the peroxidase-like activity of PRT-AuNCs, and the enhanced mechanism by Hg(II) was demonstrated to be generation of the cationic Au species and the partly oxidized Au species (Au) by Hg-Au/Au interaction.

A gold nanoparticles-modified aptamer beacon for urinary adenosine detection based on structure-switching/fluorescence-"turning on" mechanism.

A novel small molecule probe, aptamer beacon (AB), was introduced for adenosine (Ade) recognition and quantitative analysis. The Ade aptamer was engineered into an aptamer beacon by adding a gold nanoparticle-modified nucleotide sequence which is complementary to aptamer sequence (FDNA) at the 3'-end of FDNA. The fluorescence signal "turning on" was observed when AB was bound to Ade, which is attributed to a significant conformational change in AB from a FDNA/QDNA duplex to a FDNA-Ade complex.

A wireless magnetoelastic sensor for urinary 2-naphthol detection based on the precipitation of 2-naphthol with diazonium salts.

A wireless magnetoelastic sensor has been developed for the determination of 2-naphthol (2-NAP) in human urine. This method is based on the precipitation of 2-NAP with diazonium salts produced by the diazo-reaction of sulfamethoxazole (SMZ) with nitrite under a weak alkaline condition, resulting in a descending of the resonance frequency of a wireless magnetoelastic sensor. The frequence shift values (ΔF) of the sensor were directly proportional to the concentration in the range of 1.

Determination of trace formaldehyde in blood plasma by resonance fluorescence technology.

A novel method for the determination of trace formaldehyde in blood plasma has been established by using resonance fluorimetry technique. It was based on the fact that oxidation of pyronine Y by potassium bromate was catalyzed by formaldehyde in sulfuric acid. When the wavelength interval was at Δλ=0 nm, it was found that the decreased intensity (ΔF) of resonance fluorescence at 574.

Rapid simultaneous analysis of 1-hydroxypyrene, 2-hydroxyfluorene, 9-hydroxyphenanthrene, 1- and 2-naphthol in urine by first derivative synchronous fluorescence spectrometry using Tween-20 as a sensitizer.

A novel method of first derivative synchronous fluorescence was developed for the rapid simultaneous analysis of trace 1-hydroxypyrene (1-OHP), 1-naphthol (1-NAP), 2-naphthol (2-NAP), 9-hydroxyphenanthrene (9-OHPe) and 2-hydroxyfluorene (2-OHFlu) in human urine. Only one single scan was needed for quantitative determination of five compounds simultaneously when Deltalambda=10 nm was chosen. In the optimal experimental conditions, there was a linear relationship between the fluorescence intensity and the concentration of 1-OHP, 1-NAP, 2-NAP, 9-OHPe and 2-OHFlu in the range of 1.

Synchronous fluorescence determination of urinary 1-hydroxypyrene, beta-naphthol and 9-hydroxyphenanthrene based on the sensitizing effect of beta-cyclodextrin.

A novel method for the simultaneous determination of 1-hydroxypyrene (1-OHP), beta-naphthol (beta-NAP) and 9-hydroxyphenanthrene (9-OHPe) in human urine has been established by using synchronous fluorescence spectrometry. It was based on the fact that synchronous fluorescence spectrometry can resolve the broad-band overlapping of conventional fluorescence spectra, which arise from their similar molecular structures. Only one single scan is needed for quantitative determination of three compounds simultaneously when Deltalambda=15nm is chosen.

[Simultaneous determination of calcium and magnesium by calculative spectrophotometric complexometric titration].

A new spectrophotometric complexometric titration method coupled with chemometrics for the determination of mixtures of metal ions has been developed. In the method described here, the titrant is a mixture of EDTA and two indicators. In the process of titration, both the volumetric addition of titrant and the progress of titration reaction can be characterized simultaneously by chemometric calculation with the absorption spectra, and then the titration curves can be obtained.

[Determination of deoxyribonucleic acids at nanograms levels with toluidine blue by a resonance light-scattering method].

Resonance light scattering (RLS) spectra of toluidine blue (TB) with DNA was studied. The RLS of TB was greatly enhanced by DNA in the range of pH 10-11. A RLS peak at 350 nm was found, and the enhanced intensity of RLS at this wavelength was proportional to the concentration of DNA.