In this study,photovoltage technique is applied in the development of a monolithically integrated sensor for redox(reduction–oxidation)potential and pH measurement.The sensor employs the electrolyte–insulator–semiconductor structure,with deposition of a layer of gold metal on partial surface of insulator silicon dioxide.Silicon dioxide and gold layer on a single chip form two distinct sensing sites,by sharing the same measuring system,the detection of redox potential and pH variation can be realized.In this work,the sensor characteristics is tested,and the sensitivity for redox potential and pH measurement is53.8 mV/log([Fe(II)]/[Fe(III)])and 44.3 mV/pH respectively.To demonstrate the validity of the sensor in extracellular detection,neonatal rat kidney cells are cultured on the sensor surface and then packaged in a flow chamber,thus the acidification rate of metabolites and the redox potential variation in extracellular microenvironment can be continuously monitored.Experimental results indicate increasing acidification and reducing potentials under physiological conditions.The synthesis parameters have potentials in detail revelation of cell metabolism.
Jun WangChengxiong WuJie ZhouHua CaiQingjun LiuPing Wang
Mammalian olfactory systems have extraordinary ability to sense and identify various trace odorants.Taking advantages of cell culture and micro-fabrication technologies,olfactory cell-or tissue-based biosensor represent a promising platform for in vitro odorant detection.However,in vitro conditions lead to shortened cell/tissue survivals,and the working life of neuron chips is short.The purpose of this study is to develop an in vivo recording and analyzing method for long-term and repeatable detection of odor stimulation.In this study,we implanted penetrating micro-wire array electrode into the olfactory bulb of conscious rats to obtain odor-evoked electrophysiological activities.Then,we investigated the response of ensembles of mitral/tufted cells to stimulation with carvone at a number of concentrations in time and frequency domains.The stable,repeatable odorant responses from up to 16 neural regions could be obtained for at least 3 weeks.Further,we explored the concentration detection sensitivity limitation of developed method,and found the detection low limit of carvone was below10-10mol/L.The result demonstrates that the concentration range of in vivo odorant detection method is much wider than in vitro method.
Liujing ZhuangNing HuFeng TianQi DongLiang HuRong LiPing Wang
Based on patch clamp data on the ionic currents of rat taste receptor cells, a mathematical model of mammalian taste receptor cells was constructed to simulate the action potentials of taste receptor cells and their corresponding ionic components, including voltage-gated Na+ currents and outward delayed rectifier K+ currents. Our simulations reproduced the action potentials of taste receptor cells in response to electrical stimuli or sour tastants. The kinetics of ion channels and their roles in action potentials of taste receptor cells were also analyzed. Our prototype model of single taste receptor cell and simulation results presented in this paper provide the basis for the further study of taste information processing in the gustatory system.
CHEN PeiHua1, LIU Xiao-dong2, ZHANG Wei1, ZHOU Jun1, WANG Ping1, YANG Wei3 & LUO JianHong3 1Biosensor National Special Laboratory, Key Laboratory of Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China
