Catalytic conversion of sugarcane bagasse to cellulosic ethanol: TiO2 coupled nanocellulose as an effective hydrolysis enhancer.

The present study deals with the production of cellulosic ethanol from bagasse using the synthesized TiO2 coupled nanocellulose (NC-TiO2) as catalyst. Aspergillus nidulans AJSU04 cellulase was used for the hydrolysis of bagasse. NC-TiO2 at various concentrations was added to bagasse in order to enhance the yield of reducing sugars. Complex interaction between cellulase, bagasse, NC-TiO2 and the reaction environment is thoroughly studied. A mathematical model was developed to describe the hydrolysis reaction. Ethanol production from enzymatically hydrolyzed sugarcane bagasse catalyzed with NC-TiO2 was carried out using Saccharomyces cerevisiae ATCC 20602. The glucose release rates and ethanol concentrations were determined. Ethanol produced was found to be strongly dependent on pretreatment given, hydrolysis and fermentation conditions. The study confirmed the promising accessibility of NC-TiO2, for enhanced glucose production rates and improved ethanol yield.

Synergistic effect of ZnS outer layers and electrolyte methanol content on efficiency in TiO2/CdS/CdSe sensitized solar cells.

The effect of methanol content in water based polysulfide electrolytes in TiO(2)/CdS/CdSe quantum dot sensitized solar cells (QDSSCs) prepared by the SILAR method was studied. In addition, the effect of coating the mesoporous QD sensitized films with ZnS outer layers was investigated. Charge recombination reactions were measured using time resolved spectroscopic measurements. These studies reveal a synergistically beneficial effect from using ZnS layers and methanol in the polysulfide electrolyte on the control of charge transfer processes within these devices and ultimately on overall cell performance.

Gold nanoparticle fluorescent molecular beacon for low-resolution DQ2 gene HLA typing.

Coeliac disease is an inflammation of the small intestine triggered by gluten ingestion. We present a fluorescent genosensor, exploiting molecular-beacon-functionalized gold nanoparticles, for the identification of human leukocyte antigen (HLA) DQ2 gene, a key genetic factor in coeliac disease. Optimization of sensor performance was achieved by tuning the composition of the oligonucleotide monolayer immobilized on the gold nanoparticle and the molecular beacon design. Co-immobilization of the molecular beacon with a spacing oligonucleotide (thiolated ten-thymine oligonucleotide) in the presence of ten-adenine oligonucleotides resulted in a significant increase of the sensor response owing to improved spacing of the molecular beacons and extension of the distance from the nanoparticle surface, which renders them more available for recognition. Further increase in the response (approximately 40%) was shown to be achievable when the recognition sequence of the molecular beacon was incorporated in the stem. Improvement of the specificity of the molecular beacons was also achieved by the incorporation within their recognition sequence of a one-base mismatch. Finally, gold nanoparticles functionalized with two molecular beacons targeting the DQA1*05* and DQB1*02* alleles allowed the low-resolution typing of the DQ2 gene at the nanomolar level.