A strip-shield improves the efficiency of a solenoid coil in probes for high-field solid-state NMR of lossy biological samples

摘要

A strip-shield inserted between a high inductance double-tuned solenoid coil and the glass tube containing the sample improves the efficiency of probes used for high-field solid-state NMR experiments on lossy aqueous samples of proteins and other biopolymers. A strip-shield is a coil liner consisting of thin copper strips layered on a PTFE (polytetrafluoroethylene) insulator. With lossy samples, the shift in tuning frequency is smaller, the reduction in Q and RF-induced heating are all significantly reduced when the strip-shield is present. The performance of 800 MHz H-1/N-15 and H-1/C-13 double-resonance probes is demonstrated on aqueous samples of membrane proteins in phospholipid bilayers.