RESUMO
Two new amorphous molecular materials, 2,5-bis(2',5'-dimethyl-4-triphenylsilyl-phenyl)-[1,3,4]oxadiazole (BDTSO) and 2,5-bis(2',5'-dimethyl-4-triphenylsilyl-phenyl)-[1,3,4]thiadiazole (BDTST) were synthesized and investigated as hole blocking materials (HBM) for organic light-emitting diodes. The efficiency of electroluminescent device was improved by using BDTSO instead of BAlq. The current and power efficiency of the device using BDTSO as HBM is 39.6 cd/A and 13.1 lm/W at 10 mA/cm2, respectively, which is higher compared to the same values for devices using BDTST and BAq which are typically used as HBM.
RESUMO
In the present study, we exploited the superior features of peptide nucleic acids (PNAs) to develop an efficient PNA zip-code microarray for the detection of hepatocyte nuclear factor-1alpha (HNF-1alpha) mutations that cause type 3 maturity onset diabetes of the young (MODY). A multi-epoxy linker compound was synthesized and used to achieve an efficient covalent linking of amine-modified PNA to an aminated glass surface. PCR was performed to amplify the genomic regions containing the mutation sites. The PCR products were then employed as templates in a subsequent multiplex single base extension reaction using chimeric primers with 3' complementarity to the specific mutation site and 5' complementarity to the respective PNA zip-code sequence on the microarray. The primers were extended by a single base at each corresponding mutation site in the presence of biotin-labeled ddNTPs, and the products were hybridized to the PNA microarray. Compared to the corresponding DNA, the PNA zip-code sequence showed a much higher duplex specificity for the complementary DNA sequence. The PNA zip-code microarray was finally stained with streptavidin-R-phycoerythrin to generate a fluorescent signal. Using this strategy, we were able to correctly diagnose several mutation sites in exon 2 of HNF-1alpha with a wild-type and mutant samples including a MODY3 patient. This work represents one of the few successful applications of PNA in DNA chip technology.
Assuntos
Análise Mutacional de DNA/métodos , Proteínas de Ligação a DNA/genética , Diabetes Mellitus Tipo 2/diagnóstico , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Ácidos Nucleicos Peptídicos/química , Fatores de Transcrição/genética , Primers do DNA/química , Genótipo , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Humanos , Reação em Cadeia da PolimeraseRESUMO
Single-walled carbon nanotubes (SWNTs) have been chemically attached with high density onto a patterned substrate. To form the SWNT pattern, the substrate was treated with acid-labile group protected amine, and an amine prepattern was formed using a photolithographic process with a novel polymeric photoacid generator (PAG). The polymeric PAG contains a triphenylsulfonium salt on its backbone and was synthesized to obtain a PAG with enhanced efficiency and ease of spin-coating onto the amine-modified glass substrate. The SWNT monolayer pattern was then formed through the amidation reaction between the carboxylic acid groups of carboxylated SWNTs (ca-SWNTs) and the prepatterned amino groups. A high-density multilayer was fabricated via further repeated reaction between the carboxylic acid groups of the ca-SWNTs and the amino groups of the linker with the aid of a condensation agent. The formation of covalent amide bonding was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Scanning electron microscopy and UV-vis-near-IR results show that the patterned SWNT films have uniform coverage with high surface density. Unlike previously reported patterned SWNT arrays, this ca-SWNT patterned layer has high surface density and excellent surface adhesion due to its direct chemical bonding to the substrate.