Accurate pH Sensing using Hyperpolarized 129 Xe NMR Spectroscopy

Abstract

In the search for powerful non-invasive methods for pH measurement, NMR usually suffers from biases, especially for heterogeneous samples or tissues. In this Communication, using the signals of hyperpolarized ¹²⁹ Xe encapsulated in a pair of water-soluble cryptophanes, we show that a differential pH measurement can be achieved, free from most of these biases, by monitoring the difference between their chemical shifts.

Keywords: NMR spectroscopy; cryptophanes; hyperpolarized xenon; pH mapping; quantum chemistry.