Sucrose biosensor as an alternative tool for sugarcane field samples

The goal of this preliminary study was to produce an alternative tool for measuring the amount of sucrose in samples without pre-treatment and use it in the sugarcane field or mobile units. The technology developed makes payment for the sugarcane much more reliable to the producer and also can improve the quality control of the final product. A flow injection analysis system for measuring sucrose using invertase (E.C. 3.2.1.26), and glucose oxidase (E.C.1.1.3.4) (GOD) was developed. The biosensor was made using invertase and GOD incorporated into active graphite paste mixed with tetracyanoquinodimethane as mediator. The system was able to measure sucrose from 50 up to 200 mmol L-1 with a response time of 5 min using 400 mu L of sample in 100 mmol L-1 phosphate buffer pH 6.5. This sucrose biosensor showed a sensitivity of 174 +/- 8.7 nA mg(-1) of sucrose, being a robust system to measure high concentrations of sucrose in sugarcane crops and industrial and fermentation processes, without dilution or pre-treatment of the samples. Interference from organic acids, mainly ascorbic acid (+350 mV versus Ag/AgCl), was reduced in this system using the potential of 100 mV vs. Ag/AgCl. The active electrode was stable during 2 months at 4 degrees C. (c) 2007 Society of Chemical Industry.