Optical imaging is a useful tool to acquire neural activities because of its high spatial resolution, and various voltage indicators were developed to image membrane potential of neurons. Voltage sensitive dyes (VSDs) are one of them but their signal-to-noise ratio (SNR) is so low that enhancing SNR of VSD has become important. In this study, we investigated the metal-enhanced fluorescence (MEF) effect on VSD imaging by fabricating nanoplasmonic resonance chip using gold nanorods (GNRs). To amplify the fluorescence signal we used polyelectrolyte layers to control the distance between metal nanoparticles and fluorophore. Cultured rat hippocampal neurons and di-8-ANEPPS, a widely used VSD, were used to test the nanoplasmonic resonance chip, and the maximum level of fluorescence signal was obtained when nine layers of polyelectrolyte spacer were used. The nanoplasmonic resonance chip with GNR showed the possibility of the improvement in voltage imaging of neurons and is expected to enhance the availability of neuronal activity imaging in the future.

光学成像由于其较高的空间分辨率而成为获取神经活动的有用工具，因此开发了各种电压指示器来成像神经元的膜电位。电压敏感染料（VSD）就是其中一种，但是它们的信噪比（SNR）如此之低，以至于提高VSD的SNR变得很重要。在这项研究中，我们通过使用金纳米棒（GNR）制造纳米等离子体共振芯片，研究了金属增强荧光（MEF）对VSD成像的影响。为了放大荧光信号，我们使用了聚电解质层来控制金属纳米颗粒和荧光团之间的距离。培养的大鼠海马神经元和广泛使用的VSD di-8-ANEPPS被用于测试纳米等离子体共振芯片，当使用九层聚电解质间隔物时获得最大的荧光信号水平。