Search

Nanometer-scale devices are fabricated using numerous fabrication techniques since the last couple of decades. However, the advancement in nanotechnology gives new horizons to the researcher to develop nanometer-scale devices in a controlled manner while also providing high accuracy and precision with cost and time-effectiveness. This article focuses on the production of free-standing nano-scale thick Si3N4 films using Reactive Ion Etch technique. Although there are many reports in the literature on the required conditions to etch Si3N4, unfortunately, there are not many technical reports that illustrate the step-by-step fabrication and characterization together with the detailed optimization steps. Here in this study, the thinning of a membrane is achieved using CF4/Ar in controlled RF power conditions and a well-defined protocol is given with several preliminary optimization steps. By doing so, free-standing locally thinned Si3N4 membranes of about 20 nm thickness are successfully realized in a precise manner. Further assessments are given an offer to the readers of interest the ways to characterize the samples with the required cautions. The detailed procedure given here would potentially provide practical aspects for the researchers working in the field of nanofabrication. [ABSTRACT FROM AUTHOR]

Cyclotides as a cyclic peptide produced by different groups of plants have been a very attractive field of research due to their exceptional properties in biological activities and drug design applications. The importance of cyclotides as new biological activities from nature caused to attract researchers to develop new separation systems. Recent growth and development on chip-based technology for separation and bioassay especially for anticancer having sparklingly advantages comparison with common traditional methods. In this study, the microfluidic separation of Vigno 1-5 cyclotides extracted from Viola ignobilis by using polar and nonpolar forces as a liquid-liquid interaction was investigated through modified microfluidic chips and then the results were compared with a traditional counterpart technique of high-performance liquid chromatography (HPLC). The traditional process of separating cyclotides from plants is a costly and time-consuming procedure. The scientific novelty of this study is to accelerate the separation of cyclotides using modified microfluidic chips with low cost and high efficiency. The results revealed that a novel and simple microfluidic chip concept is an effective approach for separating the Vigno groups in the violet extract. We believe that the concept could potentially be utilized for further drug development process especially for anticancer studies by coupling bioassay chips as online procedures via reducing in time and cost compared with traditional offline methods. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is one of the most pressing scientific and societal issues of our age. There is an urgent need to develop new diagnostic technologies which can quickly determine whether an infection is susceptible or resistant to different treatments so that rational antibiotic prescribing can take place. The main objective of the study was therefore to develop a rapid, simple, cost effective and comprehensive antibiotic susceptibility/resistance test based on rapid nucleic acid profiling. To do so, we integrated a microelectrode sensor within a microfluidic chip that combined bacterial incubation, lysis, and electrochemical detection chambers in a single simple set-up. As a case study, Mycobacterium smegmatis was investigated as a surrogate organism for Mycobacterium tuberculosis. The novelty of the work lies in developed capability of performing incubation, lysis, fragmentation, and detection process in a comprehensive yet simple lab-on-a-chip device called 'MycoCHIP'. A gold microelectrode in combination with a specifically developed nucleic acid probe sequence for the 16SrRNA region of the mycobacterial genome were employed to monitor M. smegmatis nucleic acid sequences using Differential Pulse Voltammetry (DPV) and Square-Wave Voltammetry (SWV). The results demonstrated that it was possible to detect bacterial nucleic acid sequences and distinguish antibiotic incubated (Ab-i) cells from nonincubated (Ab-n) cells on MycoCHIP with a label-free molecular detection. The antibiotic susceptibility test showed that through measuring 16SrRNA levels from M. smegmatis ,sensitivity to antibiotic was apparent after 24 h incubation, with a developed protocol representing a potential approach to determining antibiotic susceptibility more quickly, reliable and economically than current methods. [Display omitted] • Development of an on-chip label-free molecular-based antibiotic susceptibility test for the compariatively slow-growing M. smegmatis. • MycoCHIP consists of an incubation incubation , lysis and a microelectrode functionalised with nucleic acid sequences specific for the bacteria. • Electrochemistry measurements proved that the rapid, qualitative analysis of such slow-growing bacteria was possible. • MycoCHIP proves to be capable of performing antibiotic susceptibility testing of M. smegmatis on a single chip within 24 h. • The valves developed on the chip made the opening and closing operations of the microchannels. [ABSTRACT FROM AUTHOR]