Immobilized enzymatic fluorescence capillary biosensor for determination of sulfated bile acid in urine

Expression, purification and functional characterization of a novel 3α-hydroxysteroid dehydrogenase from Pseudomonas aeruginosa

“…Some other biosensors were also sensitive at this pH [28]. The 3a-HSD exhibited substantial activity from 30 to 35°C, which was also favorable for SBAs detection [8,9,11]. Ion interference experiment suggested that the 3a-HSD activity was affected by various ions and the activating ions such as Zn 2+ could be used as activator in the enzymatic assay.…”

“…As demonstrated in the results, the 3a-HSD possessed some favorable properties for clinical applications. For example, if using the immobilized enzymatic fluorescence capillary biosensor in the measurement of SBAs, the fluorescence intensity reached the maximum at pH8.0, which is the optimum pH of the enzyme [11]. Some other biosensors were also sensitive at this pH [28].…”

“…Two enzymes -bile acid sulfatase (BSS) and 3a-hydroxysteroid dehydrogenase (3a-HSD) from Pseudomonas testosteroni were involved in the assay and rapid detection was achieved. Based on the assay reported by Tazuke, Gao et al have made significant progresses on the improvement and refinement of SBAs measurement since 1997 [6][7][8][9][10][11]. The accumulated work in our group makes it possible now to have rapid, sensitive and reliable methods for the measurement of SBAs [6][7][8][9][10][11].…”

“…Based on the assay reported by Tazuke, Gao et al have made significant progresses on the improvement and refinement of SBAs measurement since 1997 [6][7][8][9][10][11]. The accumulated work in our group makes it possible now to have rapid, sensitive and reliable methods for the measurement of SBAs [6][7][8][9][10][11]. The enzymatic assay turned out to be the solution for the clinical detection of SBAs and was used in Japan for some kinds of hepatobiliary diseases in infant and children [3,4].…”

Gold–silver-nanoclusters having cholic acid imprinted nanoshell

“…The quenching fluorescence intensity is proportional to cholic acid performed in replicates of three and the samples were analyzed in replicates of three as well. In the literature, the lowest detection limits have reported as 38.3 nmol mL −1 for deoxycholic acid (DCA) [32], 76.4 nmol mL −1 for ursodeoxycholic acid (UDCA) [33], 0.16 nmol mL −1 for bile acid [34], 5 nmol mL −1 for bile acid [35], 4.27 nmol mL −1 for cholic acid [36]. Although many methods have low detection limits, they are expensive [37][38][39].…”