Low-power optimal control pulse sequences enhance the sensitivity of 5 mm triple resonance cryogenic probe optimized for proton-detection at 1.2 GHz NMR instruments

Improving the sensitivity of nuclear magnetic resonance (NMR) spectroscopy requires advancements in both instrument technology and experimental methodology. In this study, we introduce a 5 mm triple resonance cryogenic probe optimized for proton-detection designed for 1.2 GHz instruments, leveraging optimal control pulse sequences to enhance performance. Our results show a 56% increase in average sensitivity for a benzene sample and up to a 50% improvement for a lossy concentration limited biological sample, reducing experimental time by more than a factor of two compared with the 3 mm cryogenic probes currently in use. Additionally, we systematically optimized the experimental conditions to fully exploit the capabilities of GHz-class magnets. The gain with the 5 mm cryogenic probe at 1.2 GHz was possible using low power optimal control pulses. Hence, we developed a library of optimal control triple resonance experiments, enabling boosted sensitivity for advanced NMR applications at 1.2 GHz instruments.