Fullerol–fluorescein isothiocyanate phosphorescent labeling reagent for the determination of glucose and alkaline phosphatase

The active –OH group in fullerol (F-ol) could react with the dissociated –COOH group in fluorescein isothiocyanate (FITC) to form F-ol–(FITC)n, which could emit room temperature phosphorescence (RTP) signal of F-ol and FITC on acetate cellulose membrane (ACM), respectively. Their RTP signals were enhanced by N,N-dimethylaniline (DMA). The labeling reaction between the –NCS group of FITC in DMA–F-ol–(FITC)n and the –NH2 group in wheat germ agglutinin (WGA) produced DMA–F-ol–(FITC)n–WGA, which could further take affinity adsorption (AA) reaction with bioactive substances (BS), such as glucose and alkaline phosphatase (AP), to produce DMA–F-ol–(FITC)n–WGA–BS. Both of these two products could maintain the good RTP characteristics of F-ol and FITC. Based on the facts above, a new phosphorescent labeling reagent, DMA–F-ol–FITC, was developed, and a new affinity adsorption solid substrate room temperature phosphorimetry (AASSRTP) for the determination of BS was established. This method was applied to the determination of BS in human serum and the diagnosis of diseases, with the results agreeing very well with those of enzyme-linked immunosorbent assay (ELISA). The mechanism of DMA–F-ol–(FITC)n labeling of WGA and AASSRTP for the determination of BS is discussed.