Yang Jia, Li Gongxin, Wang Wenxue, Shi Jialin, Li Meng, Xi Ning, Zhang Mingjun, Liu Lianqing
State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China; Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang, 110169, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China; Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Institute of Automation, Jiangnan University, Wuxi, 214122, China.
Biosens Bioelectron. 2021 Apr 15;178:113050. doi: 10.1016/j.bios.2021.113050. Epub 2021 Jan 30.
Human eyes rely on photosensitive receptors to convert light intensity into action potentials for visual perception, and thus bio-inspired photodetectors with bioengineered photoresponsive elements for visual prostheses have received considerable attention by virtue of superior biological functionality and better biocompatibility. However, the current bioengieered photodetectors based on biological elements face a lot of challenges such as slow response time and lack of effective detection of weak bioelectrical signals, resulting in difficulty to perform imaging. Here, we report a human eye-inspired phototransistor by integrating optogenetically engineered living cells and a graphene-based transistor. The living cells, engineered with photosensitive ion channels, channelrhodopsin-2 (ChR2), and thus endowed with the capability of transducing light intensity into bioelectrical signals, are coupled with the graphene layer of the transistor and can regulate the transistor's output. The results show that the photosensitive ion channels enable the phototransistor to output stronger photoelectrical currents with relatively fast response (~25 ms) and wider dynamic range, and demonstrate the transistor owns optical and biological gating with a significant large on/off ratio of 197.5 and high responsivity of 1.37 mA W. An artificial imaging system, which mimics the pathway of human visual information transmission from the retina through the lateral geniculate nucleus to the visual cortex, is constructed with the transistor and demonstrate the feasibility of imaging using the bioengineered cells. This work shows a potential that optogenetically engineered cells can be used to develop novel visual prostheses and paves a new avenue for engineering bio-syncretic sensing devices.
人眼依靠光敏受体将光强度转化为动作电位以进行视觉感知，因此，具有生物工程光响应元件的用于视觉假体的仿生光电探测器凭借其卓越的生物学功能和更好的生物相容性而备受关注。然而，目前基于生物元件的生物工程光电探测器面临诸多挑战，如响应时间慢以及对微弱生物电信号缺乏有效检测，导致成像困难。在此，我们报道了一种受人类眼睛启发的光电晶体管，它通过整合光遗传学工程改造的活细胞和基于石墨烯的晶体管而成。这些活细胞经工程改造带有光敏离子通道——通道视紫红质-2（ChR2），因而具备将光强度转化为生物电信号的能力，它们与晶体管的石墨烯层耦合，并能调节晶体管的输出。结果表明，光敏离子通道使光电晶体管能够输出更强的光电流，具有相对较快的响应（约25毫秒）和更宽的动态范围，并且证明该晶体管具有光学和生物门控特性，开/关比高达197.5，响应度为1.37毫安/瓦。利用该晶体管构建了一个人工成像系统，该系统模拟了人类视觉信息从视网膜经外侧膝状体到视觉皮层的传输路径，并证明了使用生物工程细胞进行成像的可行性。这项工作表明光遗传学工程改造的细胞有潜力用于开发新型视觉假体，并为工程化生物融合传感设备开辟了一条新途径。
