This paper presents a dual functional extracellular recording biosensor based on a light-addressable potentiometric sensor (LAPS). The design and fabrication of this biosensor make it possible to record both extracellular membrane potential changes and ATP release from a single taste bud cell for the first time. For detecting ATP release, LAPS chip was functionalized with ATP-sensitive DNA aptamer by covalent immobilization. Taste bud cells isolated from rat were cultured on LAPS surface. When the desired single taste bud cell was illuminated by modulated light, ATP release from single taste bud cells can be measured by recording the shifts of bias voltage-photocurrent curves (I-V curves) when the LAPS chip is working in discrete mode. On the other hand, extracellular membrane potential changes can be monitored by recording the fluctuation of LAPS photocurrent when the LAPS chip is working in continuous mode. The results show this biosensor can effectively record the enhancive effect of the bitter substance and inhibitory effect of the carbenoxolone (CBX) on the extracellular membrane potential changes and ATP release of single taste bud cells. In addition, the inhibitory effect of CBX also confirms LAPS extracellular recordings are originated from bitter signal transduction. It is proved this biosensor is suitable for extracellular recording of ATP release and membrane potential changes of single taste bud cells. It is suggested this biosensor could be applied to investigating taste signal transduction at the single-cell level as well as applied to other types of cells which have similar functions to taste bud cells.

中文翻译：

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使用光寻址电位传感器进行苦味信号转导的双功能细胞外记录

本文提出了一种基于光寻址电位传感器 (LAPS) 的双功能细胞外记录生物传感器。这种生物传感器的设计和制造使得首次记录单个味蕾细胞的细胞外膜电位变化和 ATP 释放成为可能。为了检测 ATP 释放，LAPS 芯片通过共价固定用 ATP 敏感的 DNA 适体进行功能化。从大鼠中分离的味蕾细胞在 LAPS 表面培养。当所需的单个味蕾细胞被调制光照射时，当 LAPS 芯片在离散模式下工作时，可以通过记录偏置电压-光电流曲线（IV 曲线）的变化来测量单个味蕾细胞的 ATP 释放。另一方面，当 LAPS 芯片在连续模式下工作时，可以通过记录 LAPS 光电流的波动来监测细胞外膜电位的变化。结果表明，该生物传感器可以有效地记录苦味物质对单一味蕾细胞胞外膜电位变化和ATP释放的增强作用和抑制作用。此外，CBX 的抑制作用也证实了 LAPS 细胞外记录源自苦味信号转导。证明该生物传感器适用于细胞外记录单个味蕾细胞的ATP释放和膜电位变化。