Archives for April 2013

Effects of diamond-FET-based RNA aptamer sensing for detection of real sample of HIV-1 Tat protein

April 29, 2013 By Editor

Abstract – Diamond is a promising material for merging solid-state and biological systems owing to its chemical stability, low background current, wide potential window and biocompatibility. The effects of surface charge density on human immunodeficiency virus type 1 Trans-activator transcription (HIV-1 Tat) protein binding have been investigated on a diamond field-effect transistor (FET) using ribonucleic acid (RNA) aptamers as a sensing element on a solid surface. A change in the gate potential of 91.6 mV was observed, whereby a shift in the negative direction was observed at a source-drain current of -8µA in the presence of HIV-1 Tat protein bound to the RNA aptamers. Moreover, the reversible change in gate potential caused by the binding and regeneration cycles was very stable throughout cyclical detections. The stable immobilization is achieved via RNA aptamers covalently bonded to the carboxyl-terminated terephtalic acids on amine sites, thereby increasing the sensitivity of the HIV-1 Tat protein sensor. The reliable use of a real sample of HIV-1 Tat protein by an aptamer-FET was demonstrated for the first time, which showed the potential of diamond biointerfaces in clinical biosensor applications.

Keywords – RNA aptamer, Diamond FET, HIV-1 Tat protein, Biosensor

Corresponding Author: Ruslinda Abdul Rahim
Corresponding Author’s Email: ruslinda@unimap.edu.my

Full text: PDF

Nanotechnology development status in Malaysia: Industrialization Strategy and Practices

April 25, 2013 By Editor

Abstract – Malaysia has started it own micro-technology and nanotechnology development since the early millennium year of 2000 and arise until this day. Some key plans have proven effective and others fairly not. Status about strategies and practices planned in Malaysia with some relevant finding through experiences in industries collaboration observations and UniMAP involvement in nanotechnology are presented in this paper. Some suggestion and ideas are also presented.

Keywords – Nanotechnology, R&D, Industry, Strategy, Practice, Malaysia.

Corresponding Author: Prof. Dr. Uda Hashim
Corresponding Author’s Email: uda@unimap.edu.my

Full text: PDF

New optical features to enhance solar cell performance based on porous silicon surfaces

April 18, 2013 By Editor

Abstract – Electrochemical etching is used to fabricate porous silicon (PS) surfaces for both sides of the Si wafer. The effect of PS on performance of Si solar cells is investigated and the reflected mirrors are manipulated to enhance solar cell efficiency. The process is promising for solar cell manufacturing due to its simplicity, lower cost and suitability for mass production. The PS surface has discrete pores and short-branched pores on the polished wafer side. In contrast, the etched backside of the wafer has smaller pore size, with random pores. PS formed on both sides has lower reflectivity value compared with results in other works. Solar cell efficiency is increased to 15.4% with PS formed on both sides compared with the unetched sample and other results. Using empirical models, the optical properties of the refractive index and the optical dielectric constant are investigated. The porous surface texturing properties could enhance and increase the conversion efficiency of porous Si solar cells. The obtained results are in agreement with experimental and other data.

Keywords – Porous silicon, Solar cell, Crystalline silicon, Refractive index

Corresponding Author: Prof. Dr. Yarub Al-Douri
Corresponding Author’s Email: yarub@unimap.edu.my

Full text: PDF