Room temperature phosphorescence in the liquid state as a tool in analytical chemistry

A wide-ranging overview of room temperature phosphorescence in the liquid state (RTPL1) is presented, with a focus on recent developments. RTPL techniques like micelle-stabilized (MS)-RTP, cyclodextrin-induced (CD)-RTP, and heavy atom-induced (HAI)-RTP are discussed. These techniques are mainly applied in the stand-alone format, but coupling with some separation techniques appears to be feasible. Applications of direct, sensitized and quenched phosphorescence are also discussed. As regards sensitized and quenched RTP, emphasis is on the coupling with liquid chromatography (LC) and capillary electrophoresis (CE), but stand-alone applications are also reported. Further, the application of RTPL in immunoassays and in RTP optosensing—the optical sensing of analytes based on RTP—is reviewed. Next to the application of RTPL in quantitative analysis, its use for the structural probing of protein conformations and for time-resolved microscopy of labelled biomolecules is discussed. Finally, an overview is presented of the various analytical techniques which are based on Abbreviations: 1-BrN, 1-bromonaphthalene; 2-BrN, 2-bromonaphthalene; 4-MSA, 4-maleimidylsalicylic acid; 6Br2N, 6-bromo-2-naphthol; -CDI, 6-iodo-6-deoxy-cyclodextrin; -CDI, 6-iodo-6-deoxy-cyclodextrin; A, adenine; acac, acetylacetone; AOT, di-2-ethylhexylsulfosuccinate sodium salt; AP, alkaline phosphatase; Br-CD, heptakis (6-bromo-6-deoxy-cyclodextrin); BSA, bovine serum albumin; C, cytosine; CCD, charge-coupled device; CD, cyclodextrin; CD-RTP, cyclodextrin-induced room temperature phosphorescence; CE, capillary electrophoresis; ChO, cholesterol oxidase; CPB, cetylpyridinium bromide; CPK, coproporphyrin I ketone; CPKTEE, coproporphyrin I ketone tetraethyl ester; CTA+, cetyltrimethylammonium ion; CTAB, cetyltrimethylammonium bromide; CTAC, cetyltrimethylammonium chloride; cyclic AMP, cyclic 3′,5′-adenosine monophosphate; CZE, capillary zone electrophoresis; dansyl chloride, 5-dimethylaminonaphthalene sulfonyl chloride; DMF, dimethylformamide; DNA, deoxyribose nucleic acid; DOM, n-dodecyl-d-maltoside; EA, electron affinity; EDTA, ethylenediaminetetraacetic acid; ELISA, enzyme-linked immunosorbent assay; ET, energy transfer; ferron, 8-hydroxy-7-iodo-5-quinolinesulfonic acid; FIA, flow injection analysis; G, guanine; HAI-RTP, heavy atom-induced room temperature phosphorescence; HAP, heavy atom perturber; HRP, horseradish peroxidase; IC, inner conversion; IP, ionization potential; ISC, intersystem crossing; LC, liquid chromatography; LED, light-emitting diode; LOD, limit of detection; MEKC, micellar electrokinetic chromatography; MIP, molecularly imprinted polymer; MS-RTP, micelle-stabilized room temperature phosphorescence; NS, naphthalene sulfonate; OEPK, octaethylporphine ketone; PAH, polycyclic aromatic hydrocarbon; Ph4TBP, meso-tetraphenyltetrabenzoporphyrin; PMP, pinacolyl methylphosphonate; RNA, ribose nucleic acid; R.S.D., relative standard deviation; RTPL, room temperature phosphorescence in the liquid state; SDBS, sodium dodecylbenzene sulfonate; SDS, sodium dodecyl sulfate; S/N, signal-to-noise ratio; SS-RTP, solid surface room temperature phosphorescence; T, thymine; TBP, tetrabenzoporphyrin; UV, ultraviolet; VASS, variable-angle synchronous scanning ∗ Corresponding author. Tel.: +31-204447540; fax: +31-204447543. E-mail address: [email protected] (C. Gooijer). 1 Although the abbreviation RTPL is frequently used in the literature, the specific RTPL techniques are generally designated by RTP, for instance, CD-RTP. Therefore, in the introductory sections the term RTPL will be used, while in the sections on the specific techniques the term RTP will be applied. 0003-2670/03/$ – see front matter © 2003 Elsevier B.V. All rights reserved. doi:10.1016/S0003-2670(03)00675-5 136 J. Kuijt et al. / Analytica Chimica Acta 488 (2003) 135–171 the closely related phenomenon of long-lived lanthanide luminescence. The paper closes with a short evaluation of the state-of-the-art in RTP and a discussion on future perspectives. © 2003 Elsevier B.V. All rights reserved.