# XMEA: A New Hybrid Diamond Multielectrode Array for the In Situ Assessment of the Radiation Dose Enhancement by Nanoparticles

## TL;DR

A new diamond-based device measures how nanoparticles affect radiation doses in a medium, showing gold and platinum increase doses while silver reduces them.

## Contribution

A novel hybrid diamond multielectrode array is introduced for in situ radiation dose enhancement assessment by nanoparticles.

## Key findings

- Platinum and gold nanoparticles increased radiation dose in the medium by up to 1.9 and 3.1 times, respectively.
- Silver nanoparticles reduced radiation dose in the medium by up to 37%.
- The device demonstrated a linear X-ray detector response with r² ≥ 0.9999.

## Abstract

This work presents a novel multielectrode array (MEA) to quantitatively assess the dose enhancement factor (DEF) produced in a medium by embedded nanoparticles. The MEA has 16 nanocrystalline diamond electrodes (in a cell-culture well), and a single-crystal diamond divided into four quadrants for X-ray dosimetry. DEF was assessed in water solutions with up to a 1000 µg/mL concentration of silver, platinum, and gold nanoparticles. The X-ray detectors showed a linear response to radiation dose (r2 ≥ 0.9999). Overall, platinum and gold nanoparticles produced a dose enhancement in the medium (maximum of 1.9 and 3.1, respectively), while silver nanoparticles produced a shielding effect (maximum of 37%), lowering the dose in the medium. This work shows that the novel MEA can be a useful tool in the quantitative assessment of radiation dose enhancement due to nanoparticles. Together with its suitability for cells’ exocytosis studies, it proves to be a highly versatile device for several applications.