A Photoelectrochemical Nanoreactor for Single-Cell Sampling and Near Zero-Background Faradaic Detection of Intracellular microRNA

Rational utilization of the rich light-bio-matter interplay taking place in single-cell analysis represents a new technological direction in the field. The light-fueled operation is expected to achieve advanced photoelectrochemical (PEC) single-cell analysis with unknown possibilities. Here, a PEC nanoreactor capable of single-cell sampling and near zero-background Faradaic detection of intracellular microRNA (miR) is devised by the construction of a small reaction chamber accommodating the target-triggered hybridization chain reaction for binding the metallointercalator of [Ru(bpy)(2)(dppz)](2+) as the signal reporter. Light stimulation of the dsDNA/metallointercalator adduct will induce the generation of photocurrents, underpinning a zero-biased and near zero-background PEC method toward Faradaic detection of non-electrogenic miR at the single-cell level. Using this nanotool, lower miR concentration in the near-nucleus region than that in the main cytosol was revealed.

Automated summary

This study explores a new technological direction in single-cell analysis by utilizing the rich interplay between light and bio-matter. A PEC nanoreactor is designed for single-cell sampling and detection of intracellular microRNA. The use of light stimulation enables zero-background Faradaic detection of non-electrogenic miR at the single-cell level, revealing differences in miR concentration between the near-nucleus region and the main cytosol.