The Study Of Devise And Application Of Sweet Taste Cell-Based Sensor

Cell-based sensor, using living cells as recognition elements, owns the ability of detecting physiological changes and biochemical parameters when stimulated by the tastants. It can determine the existence or the concentration of a certain tastant. The sensor works in real-time, continuously, rapidly, which leads to its abundant applications in a great deal of fields, such as medicine filtration, environment real-time detection, neurobiology, etc.Based on the successive research work on chem-bionics of our laboratory and the unique advantages of cell-based sensor, a sweet taste cell-based sensor system utilizing screen-printed carbon electrode was proposed here. The NCI-H716 cells, which have similar taste receptors and signal transduction factors with taste bud cells, were cultured on the screen-printed carbon electrode. Electrical impedance spectrum data was recorded by Princeton Applied Research 273A and Lock-in amplifier, and then processed by bistable stochastic resonance method. By analyzing system output signal-to-noise ratio, 7 concentrations of single sugar (sucrose), same sweetness of natural/artificial sweetners, and sweet tastant in a tastants mixture could be distinguished. The results are shown as follows: (1) Sweet taste cell-based sensor experimental system designSweet taste cell-based sensor experimental system was constructed following principle and correlative model of impedance spectrum, including screen-printed carbon electrode selection, electrical impedance spectrum recording system, and the automatic perfusion system and environment controlling system design. Finally, the intact system performance estimation shows that it presents good repeatability and stability.(2) NCI-H716 cell culture on screen-printed carbon electrode surfaceThe taste receptor protein of sweet and factor about taste signal transduction were expreesed in the NCI-H716 cell demonstrated by immunohistochemistry and western blot. Grounding on this, the culture method of the NCI-H716 cell on the surface of screen-printed carbon electrode was explored, as follows:Prior to seeding cell, the electrode must be treat using poly-L-lysine and laminin to enhance the attachment of electrode; the optimal cell seeding concentration was determined by impedance spectrum; the distribution and the viability of cell were performed by scanning electronic microscope and trypan blue staing respectively.(3) The optimization of sweet taste cell-based sensor systemThe optimization of the detection system mainly included the optimization of the data processing method and selection of the fixed frequency under the specific current. The contrastive results of four different data processing methods, including normalization, principle component anlysis, and bistable stochastic resonace signal-to-noise, showed that bistable stochastic resonance signal-to-noise ratio is optimal to taste cell-based sensor. The optimized stimulating frequence of NCI-H716 was 1 KHz.(4) Preliminary application of taste cell-based sensorThe single sugar, natural/artificial sweeteners with same sweet intensity and mixed solution with different basic tastant were anlysed by our sweet taste cell-based experimental system. The results showed that the same kind of sweeteners (sucrose) with different concentration can be distinguished, moreover the relationship betweent concentration and intensity is in consistency with that of sensory evaluation. Natural or artifical sweeteners with same sweet intensity have different responses. The interference effect was present in different basic tastant, so effective signal was interrupted by other background component. Sweeter sensing signals were captured in low background components. The signal was emerged, when increasing the background components.