Precision measurements are among the most important applications of quantum physics. Concepts derived from quantum information science have been explored to enhance precision measurements, as entangled states have been recognized to potentially provide sensitivity beyond the classical limit. Recent advances have also enabled the development of new types of controlled quantum systems for the realizations of solid-state qubits. Their use as quantum sensors will enable new capabilities, such as an unprecedented combination of sensitivity and spatial resolution.Unfortunately, progress towards real-world applications of quantum sensors is currently limited by the fragile nature of quantum superposition states and difficulties in preparation, control and readout of useful quantum states. Q-SEnS2 aims at overcoming these fundamental challenges by developing novel paradigms for quantum enhanced metrology and sensing in three key areas:1. Entanglement: We will explore novel classes of entangled states that promise to be more easily created and robust against decoherence.2. Control: We will develop quantum control to enhance device sensitivity to the signal, attain spectral signal resolution, and achieve increased noise immunity of the sensor.3. Readout: We will investigate quantum enhanced readout techniques to increase measurement efficiency and to reach sensor performance near the Heisenberg limit.These concepts will be implemented in an experimental platform centered on the Nitrogen- Vacancy (NV) center. The NV center electronic spin can be individually addressed, exploiting optical techniques for polarization and readout and magnetic resonance for its precise manipulation. Thanks to its excellent coherence properties, the NV center has emerged as a remarkable qubit candidate and as a versatile sensor. In Q-SEnS2 we will study NV-based magnetometry, which has the potential to be a transformative technology in fields ranging from medical imaging to materials science