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.

中文翻译：

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使用场诱导液滴电离质谱法对I型和II型光敏氧化进行无探针直接鉴定

I型和II型光敏剂通常经过精心设计以在治疗不同癌症方面获得各自的优势，而I型和II型机理，关键反应中间体以及随之产生的底物氧化产物的鉴定从未如此容易。使用我们独特的自制场致液滴电离质谱（FIDI-MS）方法，可选择性地在空气-水界面处对分子进行采样，在这里，我们可以轻松地确定后代儿童光敏剂的I型和II型机理，替莫泊芬，不添加任何探针。由三重态替莫泊芬通过I型机制夺氢而产生的不稳定的双态自由基被捕获，这表明了FIDI-MS的现场优势。