Sucrose enzyme electrode

Abstract

Americans have for a long time used sucrose extensively in most foodstuffs due to their love for sweets. Thus, it is rather important to have a method that is fast, simple, and sensitive and that could be used for the determination of sucrose in foods and agricultural products. The AOAC (Association of Official Analytical Chemists) method is accurate and precise, but very laborious and time-consuming. For some years, there has been a great deal of interest in the development of novel methods for routine analysis of sucrose (1)(2)(3)(4)(5). Several studies on the use of enzyme electrodes for the determination of sucrose have been reported (6,12,(19)(20)(21); however, these sucrose electrodes suffer from lack of either sensitivity or stability. Lately, a flow injection method for sucrose assay has been described (13,14). Although this method is rapid and precise, it is subject to interference originating from the sample matrix. Because immobilized enzyme electrodes offer many potential advantages, a sucrose enzyme electrode was constructed in this laboratory by using an oxygen electrode and three enzymes immobilized on pig intestine membranes (15). The electrode was workable and stable, but its narrow linear range and low sensitivity made it impractical for use in the food industry. Besides, the quality of the pig intestine membrane is difficult to control, thus resulting in poor reproducibility from batch to batch.Instead of a pig intestine membrane, we used more homogeneous artificial membranes, including Teflon, polyethylene, polypropylene, and cellulose acetate, for the construction of glucose and sucrose electrodes. The effects of these membranes and the amount of enzyme(s) immobilized were investigated. The applicability of the sucrose enzyme electrodes to the determination of sucrose in food and food products was evaluated. EXPERIMENTAL SECTIONThe sucrose electrode was constructed by mounting an internal membrane over the tip of an oxygen electrode jacket with an O-ring. Forty microliters of buffer solution containing 0.25 mg of bovine serum albumin (BSA) and various amounts of glucose oxidase, invertase, and mutarotase was placed on the membrane. Then, 10 pL of a 2.5% glutaraldehyde solution was added, with vigorous stirring for 30 s. The immobilized enzyme layer was allowed to form at room temperature for over 3 h. The immobilized enzyme layer was washed several times with phosphate buffer solution. Then an external membrane was placed on the enzyme layer with another O-ring. The excess membrane was cut away with a pair of scissors, and the assembly was tightly sealed with a strip of tape to prevent air from entering the enzyme layer. The completed sucrose electrode was stored in phosphate buffer (pH 6.88, 0.2 M) at 0-4 OC when it was not in use.A glucose electrode was constructed essentially by the same method as described above, except that invertase and mutarotase were not used. Two milliliters of internal filling solution (0.2 M 0003-2700/89/036 1-0782$0 1.50/0 phosphate buffer containing 0.1 M KCl, pH...

Amperometric fructose biosensor based on fructose dehydrogenase enzyme

“…The PCS + PEI polymer matrix based fructose biosensor delivered results comparable to those reported in the literature [24,[27][28][29][30][31][32][33][34] that were based on expensive immobilization processes. Bassi et al [35] immobilized FDH behind a thin non-conducting electropolymerized film of 1,3-plenylene-diamine-resorcinol for the construction of a fructose biosensor.…”

Solution to the Problem of Interferences in Electrochemical Sensors Using the Fill-and-Flow Channel Biosensor

“…Multilayer strategies, however, compound the problem of poor enzyme electrode reproducibility associated with the deposition of the enzyme layer , This concept dates back to Updike and Hicks, who used a dual electrode system to determine changes in oxygen tension for enzyme electrodes where the consumption of oxygen was used to transduce the analyte concentration . The difficulty with a dual electrode system is preparing the two electrodes so they have exactly the same transport properties and therefore give the same current for the same amount of interfering agent.…”

Measurement of glucose, sucrose and lactose in food samples with enzyme-immobilised packed-bed column reactors integrated to an amperometric enzyme electrode

“…Those biosensors have been constructed based on the sequence of the following enzymatic reactions: In the last three decades, a series of studies were carried out on the direct measurement of glucose for medical purposes up to 35-40 mm glucose concentrations and higher concentration measurement requirements for the food industry [1,2]. Studies on the enzymatic determination of sucrose on the basis of amperometric electrodes were performed in our group as well as in others [3,4]. Besides that, lactose electrodes were also prepared for food analysis up to 2-5 mm lactose concentration [5,6].…”