Development of a microfluidic device for extraction Essay

Development of a microfluidic device for extraction - Essay Example This newly microfluidic device for protein extraction may find an application in the area of proteomic research. Keywords: Microfluidic device; Sol-gel; Silica monolith; Protein extraction; Octadecyl (C18) 1. Introduction It is becoming increasingly important in the development of new medicines to use important a microfluidic tool for identifying proteins implicated in disease pathways. As the search for novel molecules to tackle diseases increases, the need to identify proteins on biological targets also increases. Efficient extraction of proteins is the most critical step for proteomics by removing the interfering materials and improving the detection sensitivity (Ahn & Wang, 2008). The recently invented silica monolithic materials are highly permeable to liquid flow and have high mass transport compared with the packed beds. Moreover, the monolithic stationary phase does not need frits, which can cause air bubbles to form and the proteins can be adsorbed into the frits and remain trapped (Cabrera et al., 2002 ). Fabrication silica monolith inside the microfluidic devices can decrease the volume of the sample and the reagents, and reduce the time of the analysis (Girault et al., 2004). Bienvenue et al. (2006) have observed that the negative aspect of the sol-gel monolith in microfluidic device is the fact that it shrinks while the monolith is formed. They further explain that this is can then cause the creation of an opening between the silica network and the microchip wall resulting in reduced surface area for protein adsoption. The aim of this contribution is to investigate the fabrication of a simple microfluidic device contained in a crack-free silica monolith to decrease sample handling, reduce contamination, be truly portable, and decrease analysis time. Moreover, its aim is to modify the surface of the silica monolith to Octadecyl silica (ODS) to use it for pre-concentration and extraction of proteins. 2. Materials and methods 2.1. Chemicals and materi als Poly (ethylene oxide) (PEO) MW=10,000 Da, trimethylchlorosilane, tetramethylorthosilicate 99 % (TMOS), chlorodimethyloctadecylsilane 95 %, 2,6-lutidine 99 %, NaCl, and trizma base were purchased from Sigma Aldrich (Poole, UK) and used as received without any further purification. Bovine pancreas insulin, bovine heart cytochrome C, chicken egg white lysozyme, ?-lactoglobulin from milk bovine, haemoglobin from human, and bovine serum albumin (BSA) were purchased from the same. Nitric acid, ammonia, toluene, HPLC grade acetonitrile (ACN), and trifluoroacetic acid (TFA) was obtained from Fisher Scientific UK Ltd. (Loughborough, UK). MicroTight Adapter was purchased from Kinesis (Cambs, UK). Poly (ether ether ketone) (PEEK) tubing was purchased from Anachem (Luton, UK). 2.2. Instrumentation Baby bee syringe pump from Bioanalytical System Inc. (West Lafayette, USA). The instrument used for detection was HPLC-UV detection: 785A UV/Visible Detector from Perkin Elmer (California, USA). T he reversed-phase analytical column was Symmetry C8 column, 4.6 mm ? 250 mm packed with silica particles (size 5 Â µm) from Thermo Fisher Scientific (Loughborough, UK). Scanning electron microscope (SEM) (EVO 60. Manufacturer: Carl Zeiss Ltd. (Welwyn Garden City, UK). SEMPREP 2 Sputter Coater from Nanotechnology Ltd. (Sandy, UK). 2.3. Fabrication of the silica-based