A diamond voltage imaging microscope

Abstract

Technologies that capture the complex electrical dynamics occurring in biological systems, across fluid membranes and at solid-liquid interfaces drive fundamental understanding and innovation in diverse fields from neuroscience to energy storage. However, the capabilities of existing voltage imaging techniques utilizing micro-electrode arrays, scanning probes, or optical fluorescence methods are respectively limited by resolution, scan speed, and photostability. Here we develop an optoelectronic voltage imaging system which overcomes these limitations by using charge-sensitive fluorescent reporters embedded within a transparent semiconducting diamond device. Electrochemical tuning of the diamond surface termination enables photostable optical voltage imaging with a quantitative linear response at biologically relevant voltages and timescales. This technology represents a major step toward label-free, large-scale, and long-term voltage recording of physical and biological systems with sub-micron resolution.The development of fluorescent molecular sensors for imaging voltage changes in biological systems has revolutionized neuroscience, providing a tool to capture neuronal activity over large areas with sub-neuron resolution both in vitro and in vivo 1-3 . However, the poor photostability of

Neuronal growth on high-aspect-ratio diamond nanopillar arrays for biosensing applications

“…Moreover, we conclude that, for sufficiently small distances between pillars (p ≤ 4 µm), the neurites are mainly suspended and they are typically in contact with the pillar top surfaces or with the upper part of the side wall. These result are particularly relevant in the light of the recently published proof of principle experiment 37 where a similar diamond platform was used to detect voltages comparable to those generated by neuronal activity assuming that neurons would maintain their functionalities despite the nanostructuring and liying on top of the pillars. Our work demonstrates that the envisioned platform is compatible with functional neurons, which is a milestone towards an NV-based sensing platform for living neurons.…”

“…Finally, the presence of different charge states of the center (i.e. NV + , NV 0 , NV − ) with different photoluminescence spectra can be used to monitor voltage changes in solutions 35,36 and has recently been shown to allow for detection of biologically relevant signal magnitudes 37 . Both nanodiamonds and bulk diamond have been used for NV-based sensing.…”

Nano-scale solution of the Poisson-Nernst-Planck (PNP) equations in a fraction of two neighboring cells reveals the magnitude of intercellular electrochemical waves

“…An interesting method to measure extracellular potentials, called diamond voltage imaging , has been recently developed, see [ 52 ]. This technology allows measuring extracellular potentials in an electrolyte solution at high spatial resolution, and it may thus open perspectives to provide direct extracellular measurements in narrow extracellular domains.…”

Neuronal growth on high-aspect-ratio diamond nanopillar arrays for biosensing applications

“…Finally, the presence of different charge states of the center (i.e. ) with different photoluminescence spectra can be used to monitor voltage changes in solutions 35 , 36 and has recently been shown to allow for detection of biologically relevant signal magnitudes 37 . Both nanodiamonds and bulk diamond have been used for NV-based sensing.…”