Room-temperature phosphorescence of dansyl chloride solution in the absence of protective medium and its medium effect

A unique fluid room-temperature phosphorescence (RTP) method, which is different from the RTP methods developed previously and needs no microscopically ordered medium, is developed. The RTP emission of dansyl chloride (DNS-Cl) and its amino acid derivatives can be induced directly in aqueous system by the addition of thallium nitrate as heavy atom perturber and sodium sulfite as deoxygenator, λexλem = 326574 nm. A good linearity between the RTP intensity and the concentration of DNS-Cl in the range 2.0 × 10−7−1.0 × 10−5 mol/l was obtained with a detection limit of 1.9 × 10−8 mol/l. A comparative study of RTP of DNS-Cl in the presence of cyclodextrins (CDs), surfactant micelle, organic solvent and bovine serum albumin (BSA) has also been carried out. This fluid RTP emission system of DNS-Cl is very transparent and stable, and can be modulated by different organic solvents. The quenching behavior of RTP by BSA presents a satisfactory linearity between the concentration of BSA and IRTP, which can be used in the quantitative analysis of BSA.