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A dynamic cell immobilization mechanism with standardized procedures for screening the surface properties of the sensor cells and the supporting matrix provides a foundation for selection of effective crosslinking agents capable of avoiding formation of large cell aggregates. It will significantly leverage the development of biosensors by enabling quantitative detection and analysis of sensor signals.

Employed in the development of continuous fermentation processes, immobilization of cells shows promising potentials in providing supports for cells to retain their viability without sacrificing physiological characteristics. The specific goal of the research at this stage is to investigate the possibilities of supporting the cells with matrices whose surface properties might offer specific sites for cell immobilization. Four different fibers, including cotton (a seed fiber), polyester (a synthetic fiber), viscose rayon (a regenerated fiber), and silk (an animal fiber), are being studied in conjunction with two types of immobilization techniques: (1) cell adhesion via van der Waal force and surface charges and (2) covalent bonding with PEI under specific conditions. The charges on the surface of E. coli have been quantified by using zeta potential, a measure of surface charges by detecting the Doppler shift of a laser beam due to the mobility of cells between diodes that switch back and forth their positive and negative charges at 60 times per second. The hydrophobic intensity of cell surfaces will be evaluated by the Microbial Adhesion To Hydrocarbon (MATH) method. The streaming zeta potential method will be conducted to evaluate the fiber surface charges. Moreover, the effects of covalent bonding on immobilization efficiency, cell viability, and biosensing characteristics will be evaluated against the adhesion mechanisms to provide insights on its applications. The biosensing characteristics of the cells will be monitored using a luminometer.