This PhD project aims to develop molecular spin-based quantum biosensors—nanoscale probes that use optical detection of quantum spin states to sense biochemical changes with exceptional sensitivity. 

Quantum biosensors are transforming medical diagnostics by harnessing quantum phenomena to detect biomarkers and disease-related indicators with greater sensitivity and specificity than conventional methods [1]. Spin-based quantum sensors use optical readout of spin states to measure magnetic fields, temperature, and strain down to the single-molecule level. 

Current state-of-the-art biosensing platforms rely on solid-state defects like nitrogen-vacancy (NV) centres in diamond, which have demonstrated powerful capabilities including nanoscale magnetic resonance imaging. However, these systems face critical limitations: their properties are constrained by the host crystal, and integration with biological targets is hindered by the rigid matrix. 

This project explores molecular quantum sensors as a highly tuneable and adaptable alternative. This approach combines principles from fluorescence microscopy and magnetic resonance, and their molecular nature allows integration into biological environments using established bioconjugation techniques such as click chemistry. This allows precise targeting and close proximity to sensing sites—essential for optimal performance. Unlike solid-state defects, molecular systems offer intrinsic design flexibility through synthetic chemistry, enabling tailored control over coherence time, spin-optical contrast, and other key parameters. This opens new avenues for optimised sensing in complex biological settings. 

Building on recent breakthroughs from the Quantum Optospintronics Group, this project will push molecular quantum sensing beyond proof-of-concept. Our prior work has demonstrated key capabilities—including optical spin readout, coherent spin control, and room-temperature operation—in chemically synthesised molecules [2]. We have also shown how synthetic design can enhance key sensing metrics such as optical-spin contrast [3].  

This PhD project will: 

• Demonstrate optical spin readout in biologically compatible molecules, drawing from established platforms such as commercial chromophores and spin labels. 

• Integrate sensors into biological environments and evaluate their ability to detect parameters such as temperature and biochemical changes. 

• Explore how synthetically tailored molecules can enhance quantum sensing performance in biological environments. 

This multidisciplinary project spans physics, chemistry, biomedicine, and quantum technologies. You will gain expertise in electron and nuclear spin resonance, cryogenic and room-temperature optical spectroscopy, and quantum-mechanical simulations. The project offers opportunities for cross-disciplinary and international collaboration, contributing to the development of next-generation quantum biosensors.