Polyelectrolyte-protected Dual-color-quantum-dot Assembled Silica Nanoparticles and Their Application in Simultaneous Fluorescence Determination of e Antigen and Surface Antigen of Hepatitis B.

Cationic poly-diallyldimethylammonium (PDADMAC), green CdTe quantum dots (QDs) or red CdS coated CdTe QDs, and anionic polyacrylic acid (PAA) were respectively assembled on the nano-carrier SiO2 to prepare green fluorescence composite nanoparticles (GF-QDs) and red ones (RF-QDs) with the structure SiO2/PDADMAC/QD/PDADMAC/PAA. The sandwich structure "PDADMAC/QD/PDADMAC" on the nano-carrier not only realized the protection to fluorescence of QDs but also avoided the fluorescence shielding of silica shell for the assembled QDs. In 7 days, the diluent solutions of GF-QD and RF-QD all have a very stable fluorescence. On the contrary, the fluorescence of diluent solutions of red and green QDs reduced by 75.99 and 94.35%, respectively. Indeed, they have not fluorescent shielding and have a very slight fluorescent enhancement. Based on GF-QD and RF-QD, the simultaneous determination of Hepatitis B e antigen and surface antigen has been established. Their determination in buffer and plasma all showed good precision and accuracy.

Multiple analytical methods for identification and quality evaluation of Fritillariae Thunbergii Bulbus based on biological single molecules by high-performance liquid chromatography.

Quantitative analysis for biological single molecules in Fritillariae Thunbergii Bulbus and identification method by chemometrics was established by using high-performance liquid chromatography. Amino acids, nucleosides, and nucleobases were quantitatively analyzed, and 11 peaks were selected for species identification. A Common pattern was established for chemometrics, and then similarity analysis, principal component analysis, and hierarchical cluster analysis heatmap were applied, and the results indicated that species were ideally identified from the adulterants as Fritillariae Cirrhosae Bulbus. This evaluation method was valuable for further quality control to select the characteristic components.

Combination with Chemometrics and Quantification for Quality Evaluation and Variety Identification of Flos Chimonanthi Praecocis by HPLC.

Flos Chimonanthi Praecocis (FCP) is one of the popular traditional Chinese medicines, which have been widely used in China. Inconspicuous appearance differences are disadvantageous for identification, and it is difficult to evaluate the quality of FCP using the current methods. In this article, a simple method that combined chemometrics and quantitative analysis was established. The samples were obtained from three typical varieties for fingerprint analysis by high-performance liquid chromatography. Contents of rutin and quercetin were determined, and then a common pattern with 16 characteristic peaks was applied for principal component analysis, similarity analysis, and the hierarchical cluster analysis heatmap (HCA heatmap) to characterize the similarity and differences among samples for identification. Furthermore, seven characteristics peaks with higher loading values were selected for chemometrics analysis after dimensionality reduction to reduce analytical difficulty, and the new common pattern showed the similar identification effects. Overall, combination with chemometrics and quantitative analysis would provide a useful and simple method for quality control of FCP in the future.

[Effect of Heat-Clearing and Detoxifying Health Function of Lonicera japonica in Rats Based on Metabonomics].

Objective: To study the metabonomics for heat-clearing and detoxifying health function of Lonicera japonica in rats. Methods: Male Wistar rats were treated with decoction of Lonicera japonica through intragastric for 5 d. GC-MS was used to detect the changes in rats serum metabolites. Mass spectrometry analysis,PCA and other technologies were used to analyze the differences among their metabolites,and analyzed the endogenous product. Results: There was a decline trend in citric acid cycle intermediates of Lonicera japonica treated group. On the contrary,amino acids and fatty acid intermediate product showed significant elevation,which revealed that the pathway of tricarboxylic acid cycle has been inhibited,and consistented with heat-clearing and detoxifying effect of Lonicera japonica. Conclusion: The metabonomics method by detecting the low-molecular-weight compounds can evaluate the heat-clearing and detoxifying health function of Lonicera japonica.

[Identification of two varieties of Citri Fructus by fingerprint and chemometrics].

Citri Fructus identification by fingerprint and chemometrics was investigated in this paper. Twenty-three Citri Fructus samples were collected which referred to two varieties as Cirtus wilsonii and C. medica recorded in Chinese Pharmacopoeia. HPLC chromatograms were obtained. The components were partly identified by reference substances, and then common pattern was established for chemometrics analysis. Similarity analysis, principal component analysis (PCA) , partial least squares-discriminant analysis (PLS-DA) and hierarchical cluster analysis heatmap were applied. The results indicated that C. wilsonii and C. medica could be ideally classified with common pattern contained twenty-five characteristic peaks. Besides, preliminary pattern recognition had verified the chemometrics analytical results. Absolute peak area (APA) was used for relevant quantitative analysis, results showed the differences between two varieties and it was valuable for further quality control as selection of characteristic components.

Combination of quantitative analysis and chemometric analysis for the quality evaluation of three different frankincenses by ultra high performance liquid chromatography and quadrupole time of flight mass spectrometry.

Frankincense has gained increasing attention in the pharmaceutical industry because of its pharmacologically active components such as boswellic acids. However, the identity and overall quality evaluation of three different frankincense species in different Pharmacopeias and the literature have less been reported. In this paper, quantitative analysis and chemometric evaluation were established and applied for the quality control of frankincense. Meanwhile, quantitative and chemometric analysis could be conducted under the same analytical conditions. In total 55 samples from four habitats (three species) of frankincense were collected and six boswellic acids were chosen for quantitative analysis. Chemometric analyses such as similarity analysis, hierarchical cluster analysis, and principal component analysis were used to identify frankincense of three species to reveal the correlation between its components and species. In addition, 12 chromatographic peaks have been tentatively identified explored by reference substances and quadrupole time-of-flight mass spectrometry. The results indicated that the total boswellic acid profiles of three species of frankincense are similar and their fingerprints can be used to differentiate between them.

Detection of DNA based on fluorescence resonance energy transfer of polyelectrolyte-protected CdTe quantum dots as energy donors.

The approach for DNA detection was established by using a fluorescence resonance energy transfer (FRET) system, in which the energy donor was poly-diallyldimethylammonium chloride-protected quantum dots and the energy receptor was ethidium bromide (EB) inserting into the double stranded DNA. The concentration of the probe DNA, EB and NaCl was optimized. Under the optimized conditions, the FRET system has a stable signal and good reproducibility. The linear range is 7.7-61.6 nM with the correlation coefficient of 0.998 and the limit of detection is 7.7 nM. This method is simple and sensitive, and makes the label-free DNA detection come true.

The expert system of genotype discrimination for D5S818 locus based on near-infrared spectroscopy-principal discriminant variate.

This paper studied the expert system of genotype discrimination for the STR locus D5S818 based on near-infrared spectroscopy-principal discriminant variate (PDV). Six genotypes, i.e. genotypes 10-10, 10-11, 11-11, 11-12, 11-13 and 13-13, were selected as research subjects. Based on the optimum polymerase chain reaction (PCR) conditions, about 54 measuring samples for each genotype were obtained; these samples were tested by near-infrared spectroscopy directly. With differences between homozygote genotypes and heterozygote ones, and differences of the total number of core repeat units between the six genotypes, two types of genotyping-tree structure were constructed and their respective PDV models were studied using the near-infrared spectra of the samples as recognition variables. Finally, based on the classification ability of these two genotyping-tree structures, an optimum expert system of genotype discrimination was built using the PDV models. The result demonstrated that the built expert system had good discriminability and robustness; without any preprocessing for PCR products, the six genotypes studied could be discriminated rapidly and correctly. It provided a methodological support for establishing an expert system of genotype discrimination for all genotypes of locus D5S818 and other STR loci.

Preparation of chlorogenic acid surface-imprinted magnetic nanoparticles and their usage in separation of traditional Chinese medicine.

The chlorogenic acid (CGA) surface-imprinted magnetic polymer nanoparticles have been prepared via water-in-oil-in-water multiple emulsions suspension polymerization. This kind of molecularly imprinted polymer nanoparticles (MIPs) had the core-shell structure with the size of about 50 nm. Magnetic susceptibility was given by the successful encapsulation of Fe(3)O(4) nanoparticles with a high encapsulation efficiency of 19.3 wt%. MIPs showed an excellent recognition and selection properties for the imprinted molecule CGA. The recognition capacity of MIPs was near three times than that of non-imprinted polymer nanoparticles (NIPs). Compared with the competitive molecule caffeic acid (CFA), the selectivity of MIPs for CGA was 6.06 times as high as that of NIPs. MIPs could be reused and regenerated, and their rebinding amount in the fifth use was up to 78.85% of that in the first use. The MIPs prepared were successfully applied to the separation of CGA from the extract of Traditional Chinese Medicine Honeysuckle.