Potentiometric determination of Delta a-l-fucosidase enzyme by using 2-chloro-4-nitrophenol-rhodamine B ion pair chemical recognition in PVC membrane sensor

• Published in: Analytical and bioanalytical chemistry 2011-05, Vol.400 (3), p.787-795
• Main Authors: Othman, Abdelhameed M, El-Houseini, M E, El-Sofy, Mohamed S, Aboul-Enein, Hassan Y
• Format: Article
• Language: English
• Subjects: Diagnosis; Enzymes; Ion pairs; Membranes; Patients; Polyvinyl chlorides; Recognition; Sensors
• ISSN: 1618-2642
• DOI: 10.1007/s00216-011-4774-0

The activity of the Delta *a-l-fucosidase (AFU) enzyme represents an excellent test for diagnosis of hepatocellular carcinoma (HCC) and fucosidosis recognized in inborn disorder of metabolism and increases the sensitivity of detection to 95.5% in patients with HCC. Therefore, the determination of the activity of AFU enzyme is very important and can be used as a screening tool for the early diagnosis of tumors for HCC patients. A simple, accurate, and sensitive potentiometric method was developed for measuring the activity of AFU. The method was based upon measuring the concentration of 2-chloro-4-nitrophenol (2-chloro-4-NP) using a 2-chloro-4-NP-rhodamine B ion pair in a PVC membrane sensor. The electrode shows a linear, reproducible, and stable potentiometric response with an anionic Nernstian slope of -51.13A-0.6 mV/decade over a wide range of concentrations 10-5--10-2 M and a detection limit of 1.0X10-6 M of 2-chloro-4-NP. The membrane exhibits a fast response time of 30 s, over a pH range of 4.0--6.5. The selectivity coefficients indicate excellent selectivity for 2-chloro-4-NP over a number of interfering species, e.g., chloride, nitrate, sulfate, chromate urea, albumin, glucose, uric acid, and total protein. The prepared sensor has been used successfully for the determination of 2-chloro-4-NP produced from the hydrolysis of 2-chloro-4-NP- Delta *a-l-fucopyranoside substrate. It was also applied for the determination Delta *a-l-fucosidase enzyme of 33 serum samples of healthy subjects and patients. The average recoveriesA-RSD for the healthy subjects, cirrhosis of chronic hepatitis C and B, and HCC serum samples were 102.6A-1.01%, 101.5A-0.95%, and 100.1A-1.1%, respectively. The results obtained are in good agreement with those obtained by standard methods.