Hill-type pH probes.
Anal Bioanal Chem 2023:10.1007/s00216-023-04515-y. [PMID:
36624196 DOI:
10.1007/s00216-023-04515-y]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/23/2022] [Accepted: 01/03/2023] [Indexed: 01/11/2023]
Abstract
Sensitive detection of the minute and yet pathologically significant pH variation is important and in fact challenging for the conventional pH probes following the Henderson-Hasselbalch equation, i.e., HH-type probes. A paradigm shift to Hill-type pH probes is ongoing. Bestowed by their positive cooperative acid-base chemistry, their pH-responsive profile follows the Hill equation, which exhibits a narrower acid/base transition width than HH-type probes and warrants a higher detection sensitivity. A polymer-based Hill-type pH-responsive material was first developed. More recently, there emerged several distinct small-molecular approaches to achieve Hill-type pH-responsive profiles. They complement the polymer-based sensing materials in applications where membrane permeability is a concern. In this trends article, we rationalize the molecular origins of their positive cooperativity in pH sensing and highlight some interesting proof-of-concept applications. We also discussed future directions of this dynamic research area.
Collapse