title: Spectral modeling for accelerated pH spectroscopy using EPR.
abstract: A data modeling and processing method for electron paramagnetic resonance (EPR)-based pH spectroscopy is presented. The proposed method models the EPR spectrum of a pH-sensitive probe in both protonated and unprotonated forms. Under slow-exchange conditions, the EPR spectrum of a sample with an unknown pH value can be accurately represented by a weighted sum of the two models, with the pH value completely determined by their relative weights. Unlike traditional pH spectroscopy, which relies on locating resonance peaks, the proposed modeling-based approach utilizes the information from the entire scan and hence leads to more accurate estimation of pH for a given acquisition time. By employing the proposed methodology, we expect a reduction in the pH estimation error by more than a factor of three, which represents an order of magnitude reduction in acquisition time compared to the traditional method.
authors.affiliation: Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA. Rizwan.Ahmad@osumc.edu
authors.forename: R
authors.initials: R
authors.lastname: Ahmad
authors.forename: L C
authors.initials: LC
authors.lastname: Potter
authors.forename: V V
authors.initials: VV
authors.lastname: Khramtsov
mesh_terms: D000465:Algorithms; D002021:Buffers; D002138:Calibration; D003625:Data Collection; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D009589:Nitrogen Oxides / Q000032:analysis; D010710:Phosphates / Q000737:chemistry; D011522:Protons; D015203:Reproducibility of Results
chemical_list: D002021:Buffers; D009589:Nitrogen Oxides; D010710:Phosphates; D011522:Protons