Applications of Chitinous Membrane from Soldier Crab on Biosensor Construction
Date Issued
2008
Date
2008
Author(s)
Hsieh, Po-Chuan
Abstract
Chitinous membranes from the dorsal part of Taiwanese soldier crabs (Mictyris brevidactylus Stimpson, 1858) were purified by a sequence of acid/base treatments (treated with 1 M HCl for 1 hr, and then with 1 M NaOH for 2 hrs). The thicknesses of the clear chitinous membranes were measured to be 20 um - 50 um, the moistures were 90% - 98%, and the molecular weights were estimated over than 1000 kDa. The natural membranes showed higher tensile strengths (5.57 MPa) than the laboratory-use thin film, Parafilm○R (4.39 MPa, 120 um in thickness). Moreover, the fine pore-sized structure of the membranes could effectively impede the diffusion of problematic biomacromolecule and charged interferents such as ascorbate through the membrane. Both the cyclic voltammetric curves and the electrochemical impedance curves revealed that the biomembrane was electrochemical inert, and the electrostatic interaction between positively charged amino groups on the surface of chitinous membrane and negatively charged human serum albumin particles could extensively reduce the electrode fouling by non-specific adsorption of serum proteins.Our study utilized the natural chitinous membrane as the supporting material for enzyme immobilization by a cross-linking reagent, glutaraldehyde. For glucose sensing, glucose oxidase (EC 1.1.3.4) was immobilized to construct a glucose sensing electrode, and a flow injection glucose biosensor. These two systems were successfully applied to evaluate the glucose content in commercial soft drinks and fermentation broths. For choline sensing, choline oxidase (EC 1.1.3.17) was immobilized to construct a flow injection choline biosensor, this system was proved to be useful in screening natural substances with acetyl cholinesterase inhibitory activities that may become potential neutraceuticals for preventing Alzheimer’s disease, and was also used to estimate serum cholinesterase activity, a useful clinical index for liver function.All the experimental results demonstrated the constructed biosensors were sensitive, reproducible, and durable to glucose or choline biosensing for at least two months.
Subjects
soldier crab
chitinous membrane
biosensor
glucose oxidase
choline oxidase
SDGs
Type
thesis
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