A supramolecular fluorescence sensor array for the differentiation of multiple anions and prediction of iodine in artificial urine using machine learning.

The simultaneous discrimination and detection of multiple anions in an aqueous solution has been a major challenge due to their structural similarity and low charge radii. In this study, we have constructed a supramolecular fluorescence sensor array based on three host-guest complexes to distinguish five anions (F-, Cl-, Br-, I-, and ClO-) in an aqueous solution using anionic-induced fluorescence quenching combined with linear discriminant analysis. Due to the different affinities of the three host-guest complexes for each anion the anion quenching efficiency for each host-guest complex was likewise different, and the five anions were well recognized. The fluorescence sensor array not only distinguished anions at different concentrations (0.5, 10, and 50 µM) with 100% accuracy but also showed good linearity within a certain concentration range. The limit of detection (LOD) was < 0.5 µM. Our interference study showed that the developed sensor array had good anti-interference ability. The practicability of the developed sensor array was also verified by the identification and differentiation of toothpaste brands with different fluoride content and the prediction of the iodine concentration in urine combined with machine learning.

Supramolecular fluorescence sensor array used for the analysis of tyrosine kinase inhibitors in biological fluids and cell imaging.

Tyrosine kinase inhibitors (TKIs) are commonly used in tumor targeting therapy. However, the rapid analysis of TKIs remains a significant challenge, especially in complex biological fluid environments. In this work, we have constructed a supramolecular fluorescence sensor array based on a cucurbituril-dye host-guest complex. The binding affinity between the three complexes and each TKI is different, resulting in different cross-response signals of the complexes to the fluorescence of each TKI. Combined with linear discriminant analysis(LDA), five kinds of TKIs can be well identified. The supramolecular fluorescence sensor array could accurately identify and distinguish the five TKIs in water and could classify mixtures containing different concentrations of TKIs in serum. The concentration and Factor 1 exhibited a good linear relationship and the detection limit (LOD) was as low as 10-7 mol L-1. The method has good reproducibility and stability. In addition, the differentiation of four clinical concentrations of first-generation TKIs further validated the potential application of arrays in drug monitoring. Finally, our proposed array enabled drug imaging in living cells. Our array platform provided the foundation for the rapid and easy monitoring of 4-anilinoquinazoline TKIs.

A white-light-emitting sensor array based on cucurbit[8]uril for quantitative detection of multicomponent nitroaniline isomers.

A white-light-emitting supramolecular complex through supramolecular interactions has been assembled; the white luminescent supramolecular complex exhibits two emission spectra. Based on this, a dual-channel white-light array sensor was constructed. The results show that it can quickly identify and detect nitroaniline isomer pollutants (p-nitroaniline, m-nitroaniline, o-nitroaniline). When these three nitroaniline isomers were added to the supramolecular white-light array sensor, the fluorescence intensity of the white-light complex decreased to varying degrees. Linear discriminant analysis (LDA) showed that the supramolecular white-light array sensor could recognize and distinguish three nitroaniline isomers and could classify mixtures containing different concentrations. Factor 1 of the array had a good linear relationship with the concentration of pollutants, and the detection limit (LOD) was as low as 0.7 µM. The method has good reproducibility and stability. In addition, it can also qualitatively detect the nitroaniline isomers in river water and contaminated rice seedling extract. It provides an ideal platform for constructing multiresponse sensors.

Supramolecular fluorescent probe based on a host-guest complex for amino acids recognition and detection in aqueous solution.

A supramolecular fluorescent probe based on a host-guest complex has been developed for amino acid recognition and detection in aqueous solution. Cucurbit[7]uril (Q[7]) with 4-(4-dimethylamino-styrene) quinoline (DSQ) formed a fluorescent probe (DSQ@Q[7]). The DSQ@Q[7] fluorescent probe nearly generated changes in fluorescence in response to four amino acids (arginine, histidine, phenylalanine and tryptophan). These changes were attributed to the host-guest interaction between DSQ@Q[7] and amino acids, which occurred as a consequence of the subtle cooperation of ionic dipole and hydrogen bonding. Linear discriminant analysis showed that the fluorescent probe could recognize and distinguish four amino acids, and a mixture with different concentration ratios could be well categorized in ultrapure water and tap water.

Supramolecular Fluorescence Sensor Array Based on Cucurbit[8]uril Complexes Used for the Detection of Multiplex Quaternary Ammonium Pesticides.

The simultaneous detection of multiple quaternary ammonium pesticides (QAPs) in water is a challenge due to their high solubility in water and similar structures. In this paper, we have developed a quadruple-channel supramolecular fluorescence sensor array for the simultaneous analysis of five QAPs, including paraquat (PQ), diquat (DQ), difenzoquat (DFQ), mepiquat (MQ), and chlormequat (CQ). Not only were QAP samples of different concentrations (10, 50, and 300 µM) in water distinguished with 100% accuracy but also single QAP and binary QAP mixed samples (DFQ-DQ) were sensitively quantified. Our experimental interference study confirmed that the developed array has good anti-interference ability. The array can quickly identify five QAPs in river and tap water samples. In addition, it also qualitatively detected QAP residues in Chinese cabbage and wheat seedlings extract. This array has rich output signals, low cost, easy preparation, and simple technology, demonstrating great potential in environmental analysis.

A supramolecular fluorescence array sensor for toxic heavy metal ion detection in environmental water and rice seedling extracts.

A supramolecular fluorescence array sensor based on cucurbituril-dye host-guest complexes (6-QAA@Q[7], PyY@Q[7], and TO@Q[8]) was constructed. The results showed that it can quickly identify and detect toxic heavy metal ions, such as Ag+, Cr3+, Hg2+, Ni2+, and Pb2+. When these five toxic heavy metal ions were added to the supramolecular fluorescence array sensor, different fluorescence responses were produced due to the different binding capacities of the metal ions to the cucurbituril-dye complex. Linear discriminant analysis (LDA) showed that the supramolecular fluorescence array sensor could identify and distinguish these five toxic heavy metal ions and a mixture containing different concentration ratios could be classified. The linear correlation between the metal ion concentration and factor 1 (F1) was strong, and the detection limit (LOD) was as low as 10-6-10-7 mol L-1. These five toxic heavy metal ions in environmental water and rice seedling extracts were identified using the supramolecular fluorescence array sensor. This sensor provides a quick and convenient method for monitoring toxic heavy metal ions in sewage.

A colorimetric supramolecular sensor array based on charge-transfer complexes for multiplex aniline and phenolic pollutants detection.

In order to effectively monitor toxic and harmful substances in sewage discharge, a rapid, highly sensitive detection of complex pollutants with similar structures has become an urgent problem to be solved. In this paper, a supramolecular colorimetric array sensor based on charge-transfer complex was constructed, which can quickly detect aniline and phenol pollutants (such as p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, m-aminophenol, hydroquinone, and resorcinol) with similar structures. When six anilines and phenol isomers with similar structures were added to the supramolecular colorimetric array sensor, different color changes were produced under natural light. Linear discriminant analysis (LDA) showed that the supramolecular colorimetric array sensor could recognize and distinguish these isomers, and a mixture with different concentration ratios could be well categorized. The total Euclidean distance (TED) of an array with pollutant concentrations had a good linear correlation, and the detection limit (LOD) was as low as 10-5-10-6 mol L-1. Six anilines and phenol isomers in real samples were identified by supramolecular colorimetric array sensor. 1H NMR results showed that the formation of charge transfer complexes in Q[8] cavity may be the cause of color change. This work provides a fast and convenient experimental basis for monitoring the complex structure pollutants in sewage discharge.

An outbreak of type π vaccine-derived poliovirus in Sichuan province, China: emergence and circulation in an under-immunized population.

BACKGROUND: During August 2011-February 2012, an outbreak of type Π circulating vaccine-derived poliovirus (cVDPVs) occurred in Sichuan Province, China. METHODS: A field investigation of the outbreak was conducted to characterize outbreak isolates and to guide emergency response. Sequence analysis of poliovirus capsid protein VP1 was performed to determine the viral propagation, and a coverage survey was carried out for risk assessment. RESULTS: One clinical compatible polio case and three VDPV cases were determined in Ngawa County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan Province. Case patients were unimmunized children, 0.8-1 years old. Genetic sequencing showed that the isolates diverged from the VP1 region of the type Π Sabin strain by 5-12 nucleotides (nt) and shared the same 5 nt VP1 substitutions, which indicate single lineage of cVDPVs. Of the 7 acute flaccid paralysis cases (all>6 months) reported in Ngawa Prefecture in 2011, 4 (57.1%) cases (including 2 polio cases) did not receive oral attenuated poliovirus vaccine. Supplementary immunization activities (SIAs) were conducted in February-May, 2012, and the strain has not been isolated since. CONCLUSION: High coverage of routine immunization should be maintained among children until WPV transmission is globally eradicated. Risk assessments should be conducted regularly to pinpoint high risk areas or subpopulations, with SIAs developed if necessary.