# Single–Molecule Biodosimetry

## TL;DR

This paper introduces a new method using nanopore sensors to measure DNA damage from radiation at the single-molecule level, offering potential for rapid and personalized radiation dosimetry.

## Contribution

The study introduces a novel single-molecule biodosimetry approach using resistive-pulse nanopore sensors to quantify DNA damage from radiation.

## Key findings

- Resistive-pulse nanopore sensors can measure DNA double-strand scissions in response to γ radiation dose.
- The response curve resembles cell survival rates and is explained by radical damage and bimolecular radical loss.
- The method supports rapid dosimetry for triage and monitoring radiotherapy effectiveness.

## Abstract

Inferring characteristics of radiation exposure using
biological
molecules is extremely challenging. Current methods, in particular,
lack a clear connection between dose and molecular response. Here,
we demonstrate that resistive–pulse nanopore sensors enable
single–molecule biodosimetry by quantifying the frequency of
double–strand DNA scissions versus γ radiation dose.
The resulting response curve shows an elongated Gaussian behavior,
reminiscent of cell survival rates versus dose. We demonstrate that
the competition of radical damage of DNAi.e., single–strand
lesions that lead to breakagewith bimolecular radical loss
captures the form of the response. Our sensors and protocol provide
a foundation for numerous technological advances. These include rapid
dosimetry for triage in emergency situations and ex vivo monitoring
of radiotherapy effectiveness in order to tailor treatment to patient–
and tumor–specific response.