Hybrid nanodiamond quantum sensors enabled by volume phase transitions of hydrogels

Abstract

Diamond nitrogen-vacancy (NV) center-based magnetometry provides a unique opportunity for quantum bio-sensing. However, NV centers are not sensitive to parameters such as temperature and pressure, and immune to many biochemical parameters such as pH and non-magnetic biomolecules. Here, we propose a scheme that can potentially enable the measurement of various biochemical parameters using diamond quantum sensing, by employing stimulus-responsive hydrogels as a spacing transducer in-between a nanodiamond (ND, with NV centers) and magnetic nanoparticles (MNPs). The volume phase transition of hydrogel upon stimulation leads to sharp variation in the separation distance between the MNPs and the ND. This in turn changes the magnetic field that the NV centers can detect sensitively. We construct a temperature sensor under this hybrid scheme and show the proof-of-the-principle demonstration of reversible temperature sensing. Applications in the detection of other bio-relevant parameters are envisioned if appropriate types of hydrogels can be engineered.

Real-time nanodiamond thermometry probing in vivo thermogenic responses

“…The sensor reads temperature as a frequency shift of the optically detected magnetic resonance (ODMR) of nitrogen-vacancy (NV) defect centers, which mainly originates from thermal lattice expansion ( 22 ). The NV sensory core is deeply embedded in the diamond lattice and immune to various biological environmental factors ( 23 – 25 ). Implementing this quantum sensor in more complex organisms will enable monitoring of their site-specific thermal activities in real time.…”

Interplay of quantum phase transition and flat band in hybrid lattices

“…The quantum phase transition (QPT), driven by quantum fluctuations in many-body systems, is one of the most fundamental and significant concepts in physics since it can offer the important resources for quantum metrology [1][2][3] and quantum sensing [4][5][6]. For example, the generation of manybody entanglement through QPT enables precision metrology to reach the Heisenberg limit [7,8].…”

Carbon Nanostructure-based Sensors: A Brief Review on Recent Advances

“…Zhang et al [169] proposed the employment of stimulusresponsive hydrogels as a spacing transducer in between an ND with NV centers and magnetic nanoparticles (MNPs) intending to enable the use of ND with NV centers to measure biochemical parameters applying diamond quantum sensing. ND was adopted as core, with a shell of hydrogel and MNPs coating on the surface.…”