Biorecognition Ability of Polysaccharides as Piezo Quartz Biosensors
Piezoquartz biosensors (PQB) which are analytical devices for recognition of biochemical interactions have recently attracted increasing interest from different researchers such as analysts, immune-chemists, medical doctors, environmentalists, etc. This is due to the advantages of PQB for having high detection sensitivity (at ng and mg level depending on the mass of sorbates or micro-organisms) and the ability to monitor biochemical reactions in turbid or highly coloured liquids (including in biological fluids) in real time. The use of additional markers and preliminary sample preparation are not required in this biorecognition process. This paper reports on the principle of the PQB and the design units to perform analysis in static and dynamic conditions using different types of biomolecules (immunoglobulins, DNA, lipopolysaccharides, glycoconjugates, hapten-protein conjugates and polysaccharides). Research results performed at the Department of Chemistry, Lipetsk State Technical University (Russia) and School of Physics, College of Natural Sciences, UDOM (Tanzania) are presented. The report aims to review various examples of use of carbohydrate molecules and glycoconjugates in the design of the PQB. These examples include the following: use of sulphated polysaccharides to increase the strength of the sensor’s bio-laye;, use of glycolipids such as O-antigens of bacteria (Yersinia enterocolitica) with different chemical structures in the development of immunosensors for the determination of specific immunoglobulins at 3-100 mg/ml levels in serum; and the use of polysaccharide hydrogels of the first chemical structure (hyaluronic acid, zosteran and neutral and acidic polysaccharide fractions isolated from water hyacinth Eichhornia crassipes) in studying their effectiveness in Pb2 +ions sorption.
Key Words: Quartz crystal microbalance, piezoquartz biosensors (PQB), bioreceptor molecules, polysaccharide hydro gel, liquid media, “dip and dry”, flow injection analysis (FIA), adsorption, heavy metals.