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Biomedical subjects

Liu Ran

Publications and source records attributed to Liu Ran.

2 recordsLinked to original sources

A sequential injection analysis/chemiluminescent plant tissue-based biosensor system for the determination of diamine.

In this paper, a new chemiluminescent plant tissue-based biosensor for diamine detection was presented by employing sequential injection analysis (SIA), which facilitates precise fluidic handling and lower consumption of sample and reagents. Pea-seedling tissue acted as the molecular recognition element and was packed in a mini-PTFE column and further incorporated in the SIA system. The analysis of diamines, such as putrescine and cadaverine, is based on an enzymatic conversion which takes place in the plant tissue column to produce hydrogen peroxide. The formed hydrogen peroxide was detected by a chemiluminescence reaction involving luminol and Co(2+). Under the optimal conditions, the linear calibration graphs were obtained within 0.2-80 microM (putrescine) and 0.5-100 microM (cadaverine). The detection limits of 0.03 and 0.06 microM were achieved for putrescine and cadaverine, respectively, along with the relative standard deviations of 2.14% and 3.08% (n=11) and a sampling frequency of 40 h(-1). The present biosensor has been used for the analysis of diamine in fish samples with an acceptable accuracy.

Biological Assay↗

A novel flow-injection chemiluminescence system for the determination of guanine.

A novel flow-injection chemiluminescence (CL) method for the determination of guanine was developed. The procedure is based on the CL reaction of guanine with hydrogen peroxide in borax buffer (pH 8.5) with Co2+ as a catalyst. The calibration graph is linear within the range of 3 x 10(-7)-9 x 10(-5) g/mL. A detection limit of 1 x 10(-7) g/mL, along with a relative standard deviation of 2.23% (3 x 10(-7) g/mL guanine, n = 11), were obtained. The present procedure was applied to the measurement of guanine in urine with recoveries of 97.5-107.5%. A possible CL mechanism of the reaction system is proposed.

Buffers↗