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Main Authors: Li, Min, Zhang, Qi, Kong, Xi, Zhao, Sheng, Pan, Bin-Bin, Sun, Ziting, Yu, Pei, Wang, Zhecheng, Wang, Mengqi, Ji, Wentao, Kong, Fei, Cheng, Guanglei, Wu, Si, Wang, Ya, Chen, Sanyou, Su, Xun-Cheng, Shi, Fazhan
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2512.10269
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author Li, Min
Zhang, Qi
Kong, Xi
Zhao, Sheng
Pan, Bin-Bin
Sun, Ziting
Yu, Pei
Wang, Zhecheng
Wang, Mengqi
Ji, Wentao
Kong, Fei
Cheng, Guanglei
Wu, Si
Wang, Ya
Chen, Sanyou
Su, Xun-Cheng
Shi, Fazhan
author_facet Li, Min
Zhang, Qi
Kong, Xi
Zhao, Sheng
Pan, Bin-Bin
Sun, Ziting
Yu, Pei
Wang, Zhecheng
Wang, Mengqi
Ji, Wentao
Kong, Fei
Cheng, Guanglei
Wu, Si
Wang, Ya
Chen, Sanyou
Su, Xun-Cheng
Shi, Fazhan
contents The investigation of biomolecular interactions at the single-molecule level has emerged as a pivotal research area in life science, particularly through optical, mechanical, and electrochemical approaches. Spins existing widely in biological systems, offer a unique degree of freedom for detecting such interactions. However, most previous studies have been largely confined to ensemble-level detection in the spin degree. Here, we developed a molecular interaction analysis method approaching single-molecule level based on relaxometry using the quantum sensor, nitrogen-vacancy (NV) center in diamond. Experiments utilized an optimized diamond surface functionalized with a polyethylenimine nanogel layer, achieving $\sim$10 nm average protein distance and mitigating interfacial steric hindrance. Then we measured the strong interaction between streptavidin and spin-labeled biotin complexes, as well as the weak interaction between bovine serum albumin and biotin complexes, at both the micrometer scale and nanoscale. For the micrometer-scale measurements using ensemble NV centers, we re-examined the often-neglected fast relaxation component and proposed a relaxation rate evaluation method, substantially enhancing the measurement sensitivity. Furthermore, we achieved nanoscale detection approaching single-molecule level using single NV centers. This methodology holds promise for applications in molecular screening, identification and kinetic studies at the single-molecule level, offering critical insights into molecular function and activity mechanisms.
format Preprint
id arxiv_https___arxiv_org_abs_2512_10269
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Quantum relaxometry for detecting biomolecular interactions with single NV centers
Li, Min
Zhang, Qi
Kong, Xi
Zhao, Sheng
Pan, Bin-Bin
Sun, Ziting
Yu, Pei
Wang, Zhecheng
Wang, Mengqi
Ji, Wentao
Kong, Fei
Cheng, Guanglei
Wu, Si
Wang, Ya
Chen, Sanyou
Su, Xun-Cheng
Shi, Fazhan
Quantum Physics
Biological Physics
The investigation of biomolecular interactions at the single-molecule level has emerged as a pivotal research area in life science, particularly through optical, mechanical, and electrochemical approaches. Spins existing widely in biological systems, offer a unique degree of freedom for detecting such interactions. However, most previous studies have been largely confined to ensemble-level detection in the spin degree. Here, we developed a molecular interaction analysis method approaching single-molecule level based on relaxometry using the quantum sensor, nitrogen-vacancy (NV) center in diamond. Experiments utilized an optimized diamond surface functionalized with a polyethylenimine nanogel layer, achieving $\sim$10 nm average protein distance and mitigating interfacial steric hindrance. Then we measured the strong interaction between streptavidin and spin-labeled biotin complexes, as well as the weak interaction between bovine serum albumin and biotin complexes, at both the micrometer scale and nanoscale. For the micrometer-scale measurements using ensemble NV centers, we re-examined the often-neglected fast relaxation component and proposed a relaxation rate evaluation method, substantially enhancing the measurement sensitivity. Furthermore, we achieved nanoscale detection approaching single-molecule level using single NV centers. This methodology holds promise for applications in molecular screening, identification and kinetic studies at the single-molecule level, offering critical insights into molecular function and activity mechanisms.
title Quantum relaxometry for detecting biomolecular interactions with single NV centers
topic Quantum Physics
Biological Physics
url https://arxiv.org/abs/2512.10269