[Fluorescent labeling of latent fingerprints with metallic ions modified ZnS/PAMAM nano-composites].

Abstract Effects of metallic ions, such as Zn2+ , Mn , Cd2+, Na+, K+, Ag, CuZ+ and PbZ, on the photoluminescence properties of ZnS(ZINC sulfide) QDs (quantum dots)/poly (amido amine) (PAMAM) dendrimer nanocomposites(NCs) with blue emission under the irradiation of UV light were studied. The results show that the effects of different metallic ions on the photoluminescence properties of the prepared ZnS QDs were different. Zn+ , Mn2+ and Cd2+ ions enhance the PL(photoluminescence) intensity; Na+ and K+ ions don't change the PL intensity obviously while Ag+, Cu2+ and Pb2+ quench it. Compared with ZnS/PAMAM NCs, fingerprints treated with ZnxCd1-x) S/PAMAM NCs emitted brighter blue light, the contrast between abstracts and fingerprints was more obvious, which shows good reference

[Fluorescent labeling of latent fingerprints with PAMAM capped ZnS QDs].

Stable PAMAM (polyamidoamine) capped ZnS (zinc sulfide) QDs (quantum dots) were prepared and characterized with UV-Vis spectrum and PL(photoluminescence) emission spectrum on the base of coordination of Zn2+ ions with PAMAM dendrimers. The results show that Zn2+ ions coordinated with N atoms of PAMAM ligand and the saturated coordinating time is about 6 h; PAMAM capped ZnS QDs emitted strong blue light under the irradiation of UV light at the wavelength of 365 nm, and the PL emission peak is at about 500 nm. Finally, the prepared PAMAM capped ZnS QDs were applied in the fluorescent labeling of latent fingerprints on tinfoils; Latent fingerprints emitting strong blue light and were successfully detected with good resolving rate.

[Study of photoluminesence property of CdS/PAMAM nanocomposites].

The photoluminescence property of CdS/PAMAM nanocomposites in water at different ratio of Cd2+ to PAMAM(r) was studied by fluorescence emission spectrum, and the according mechanism was explored. The results indicate that in the irradiation of UV light at the wavelength of 330 nm, two peaks were shown in the fluorescence emission spectrum of CdS/PAMAM nanocomposites. One peak was attributed to PAMAM dendrimers, and the another came from CdS QDs. The strength of the frontier fluorescence emission peak became weaker and weaker, and at last disappeared with the enhancement of the ratio of Cd2+ to PAMAM; the strength of the latter fluorescence emission peak became stronger, which indicates that the electron at valence band of N atom in amines of dendrimers was transferred to CdS QDs. Oil latent finger marks deposited on transparent adhesive tapes surface treated with pure PAMAM solution with blue photoluminescence was not clear enough because of the blue light emitted from the impurity in adhesive tapes; Latent finger marks emitted strong yellow light and were successfully detected with good resolving rate with CdS/dendrimer solution with r of 10, which shows good reference value for detecting finger marks on surfaces with impurities emitting different photoluminescence colors.

[Study on amidation reaction between CdS/PAMAM and amino acid and its application to latent fingerprint development].

A new method for the development of latent fingerprints by CdS/PAMAM nanocomposites was explored in the present research. Amidation reaction between terminal carboxylate groups of amino acids and terminal amino groups of PAMAM G4. 5 dendrimers was studied by FTIR spectrometry. The reacting processes under different conditions were monitored by H(1267/1735) (the relative ratio of peak height) in order to find out the optimized condition and developing method. The results indicated that the reacting processes were affected remarkably by the changes in temperature. The reaction was efficient under 90 degrees C within 4 hours, while the reacting speed decreased after 3 hours under 120 degrees C. CdS/PAMAM was utilized as the latent fingerprint developing reagent and compared with the routine one. The results indicated that the fluorescence intensity of the former is 65 times higher than that of the latter. Great predominance in florescence could be observed when CdS/PAMAM and the routine developing reagent were compared. Latent fingerprints on the surface of different objects were developed under 120 degrees C within 0.5-3 h. Good developing results could be obtained under the optimized condition. The method is simple, rapid, highly sensitive, safe and economical.

[Identification of Nam Dinh virus in China].

During 2009-2012, the Nam Dinh virus (NDiv) was detected from the samples of Culex pipiens quinquefasciatus in Shenzhen China. In this study, cell culture,SYBR Green I based real time RT-PCR and RT-PCR were performed to analyze the cell susceptibility and other biological characteristics of the NDiV isolates. The results showed that C6/36 cell line was susceptible to four isolates of Culex pipiens quinquefasciatus. The "S" type amplification curve and specific melting curve were obtained in the realtime fluorescence quantitative RT-PCR based on SYBR Green I for the detection of the NDiV from the mosquito. The target bands from the RdRp gene and partial fragment of ZmHel1 gene were observed using agarose gel electrophoresis. Both the nucleotide and amino acid sequences of four Shenzhen isolates showed more than 99.00% homology with the Vietnam representative NDiV strain (02VN178). Phylogenetic analysis showed that four Shenzhen isolates shared the same evolution branch as the Vietnam representative NDiV strain. This is the first report of NDiV in China.

Application of photoluminescent CdS/PAMAM nanocomposites in fingerprint detection.

Uniform and well-dispersed photoluminescent semiconductor CdS (cadmium sulfide) QDs (quantum dots) were in situ prepared inside Generation 4.0-NH(2) PAMAM (polyamidoamine) dendrimers in methanol, methanol and water mixed solutions of volume ratio 1:9, respectively. The prepared solutions containing photoluminescent semiconductor CdS QDs were utilized for detection of cyanoacrylate ester fumed fingerprints on tinfoil. The results show that fumed latent fingerprints treated with prepared CdS/PAMAM nanocomposites in methanol, 1:9 methanol:water mixed solutions emit pale yellow-green and orange luminescence respectively under ultraviolet excitation of 365 nm from an UV LED. Fumed fingerprints were successfully detected with good resolving rate and the mechanism was studied in detail.