Effects of Thermal Oxidation and Proton Irradiation on Optically Detected Magnetic Resonance Sensitivity in Sub-100 nm Nanodiamonds

• DOI: 10.1021/acsami.4c08780
• Publication Date: 2025-03-30T13:50:48Z
• Authors: Pietro Aprà; Gabriele Zanelli; Elena Losero; Nour-Hanne Amine; Greta Andrini; Mario Barozzi; Ettore Bernardi; Adam Britel; Roberto Canteri; Ivo Pietro Degiov...; Lorenzo Mino; Ekaterina Moreva; Paolo Olivero; Elisa Redolfi; Claudia Stella; Sofia Sturari; Paolo Traina; Veronica Varzi; Marco Genovese; Federico Picollo
• Keywords: Proton magnetic resonance; Thermal oxidation

In recent decades, nanodiamonds (NDs) have emerged as innovative nanotools for weak magnetic fields and small temperature variation sensing, especially in biological systems. At the basis of use NDs quantum sensors are nitrogen-vacancy center lattice defects, whose electronic structures influenced by surrounding environment can be probed optically detected resonance technique. Ideally, limiting NDs' size much possible is important to ensure higher biocompatibility provide spatial resolution. However, reduction typically worsens sensing properties. This study endeavors obtain sub-100 nm suitable used sensors. Thermal processing surface oxidations were performed purify control their chemistry size. Ion irradiation techniques also employed increase concentration centers. The impact these processes was explored terms (diffuse reflectance infrared Fourier transform spectroscopy), structural optical properties (Raman photoluminescence dimension (atomic force microscopy measurements), sensitivity. Our results demonstrate how optimization defect density enhancement reduce detrimental reduction, opening possibility minimally invasive high-performance physical quantities environments with nanoscale