A Study Of Nickel Hydroxide Modified Sweet Taste Sensor

With the tremendous progress in the field of human taste receptor in vitro, artificial taste system has been further developed. As one of the five basic taste, sweet taste detection has been the research focus. But since sweet substances are non-electrolytes, it has been difficult for taste sensors to detect them. This paper provides a novel and effective sweet taste sensor, its production methods and the electrode used are discussed, then we use it to detect sweet taste of natural sweet substances and actual samples.(1) In this paper, we modified glassy carbon electrode, carbon paste electrode and nickel electrodes to construct three sweet taste sensors, simultaneously we optimized experimental conditions and got three sensors under these conditions. Comparing the performance of three sweet taste sensors by electrochemical methods, and combined with the actual usage, we ultimately chose the Ni(OH)2/Ni sweet taste sensor. Then through the experiments, the measurement conditions of the sweet taste sensor are that the voltage is0.47V and buffers used is1M KOH solution when we detect samples. The effective life of sweet taste sensor is up to16days.(2) We used the new sensor to detect glucose, sucrose, xylitol, erythritol, mannitol, maltose, lactose, fructose, isomalto-oligosaccharides, sorbitol. By cyclic voltammetry and amperomeric titration, we found that Ni(OH)2/Ni electrode had a very good response and excellent sensitivity to these10kinds of natural sweet substances, and the limit of detection of these natural sweet substances were all less than100μM. In addition, the experimental results shows that there is a linear relationship between the current value measured by the sensor and the concentration of natural sweet substances within the concentration range100μM-100μM, it indicates that we can use the new sweet sensor for quantitative detection of these sweet substances within this range.The signal measured by the sweet sensor was processed to obtain the characteristic signal values for better stability (coefficient of variation is less than5%). Then we made correlation analysis between characteristic signal value and the relative sweetness of these sweet substances, the correlation coefficient was0.868, indicating the characteristic signal values measured by sweet taste sensor can be used to characterize the relative sweetness of natural sweet substance (except sugar).(3) In this section, we used the new sensor to detect the actual sample. Firstly, we obtained the total sugar content by titration, measured the Brix by the pocket refractometer, and got sensory scores in terms of sweetness by sensory experiments. Then through comparative analysis of characteristic sensor signal values of fresh juice obtained by sweet sensor and these results obtained above, We found that characteristic sensor signal values had a very good correlation with sensory scores and total sugar content, the correlation coefficients were respectively0.8525and0.8225, while the correlation coefficient of Brix and sweetness sensory score was only0.4624. It shows that characteristic sensor signal values measured by sweet sensor can characterize sensory scores and total sugar content, and better than the Brix.In conclusion, this paper provides a novel and effective sweet taste sensor of the electronic tongue, improving its ability of detecting sweetness. It is rapid and easy to use the sensor to detect sweet taste of natural sweet substances and actual samples.