Probe‐Free Direct Identification of Type I and Type II Photosensitized Oxidation Using Field‐Induced Droplet Ionization Mass Spectrometry. (17th September 2020)

• Record Type: Journal Article
• Authors: Mu, Chaonan; Wang, Wei; Wang, Jie; Gong, Chu; Zhang, Dongmei; Zhang, Xinxing
• Is Part Of: Angewandte Chemie. Volume 132:Number 48(2020)
• Page Start: 21699
• Page End: 21703
• Publication Date: 2020-09-17
• Subjects: field-induced droplet ionization -- lipid oxidation -- mass spectrometry -- photodynamic therapy -- type I and II mechanism; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202010294
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: While Type I and Type II photosensitizers are often carefully tailored to achieve their respective advantages in treating different cancers, the identifications of the Type I and II mechanisms as such, the key reaction intermediates, and the consequent oxidation products of the substrates have never been easy. Using our unique home‐built field‐induced droplet ionization mass spectrometry (FIDI‐MS) method that selectively samples molecules at the air–water interface, here we show the facile determination of both Type I and II mechanisms of a poster‐child photosensitizer, temoporfin, without the addition of any probes. The unstable doublet radical resulting from the hydrogen abstraction by the triplet temoporfin through the Type I mechanism is captured, manifesting the in situ advantage of FIDI‐MS. We anticipate that the method developed in this study can be widely utilized in the future designs of novel photosensitizers and the screening of their photosensitization mechanisms. Abstract : Mechanistic studies of photosensitized oxidation reactions have now been made easier. Using the unique field‐induced droplet ionization mass spectrometry method, the types of photosensitization and oxidation products of the substrates can now be identified with a single shot of sampling.