Quantum sensing with the nitrogen–vacancy (NV) center in diamond provides a route for nanoscale NMR and EPR spectroscopies of single to a few molecules. Combined stabilization of shallow NVs and surface functionalization with molecules of interest enables chemical sensing with high sensitivity and nanoscale localization under ambient conditions. In particular, the use of NVs has been proposed to investigate photogenerated spin-correlated radical pairs (SCRPs) in biomolecules by tracking charge separation and recombination, spin dynamics, and most recently, spin polarization attributed to chirality-induced spin selectivity (CISS). The use of NVs could provide insight into the complex spin dynamics involved in SCRP generation and spin evolution in systems ranging from proteins to molecular qubits for quantum information science. Still, challenges in surface chemistry, SCRP spin dynamics, and NV photostability under blue and UV irradiation necessary for exciting SCRPs have impeded experiments to probe photochemical reactions. Dr. Abendroth will address each of these challenges and share the first experimental detection of photogenerated radical pairs with single NVs, laying the groundwork for future photochemical experiments with quantum sensors.