In this study, a novel biosensor based on enzyme extracts from soybean seed hulls has been prepared, which demonstrated promising results in the detection of hydrogen peroxide and phenol. The biosensor preparation is straightforward and inexpensive, and the response time is 50 s. The optimum conditions of pH and temperature are a pH of 7.4 and a temperature of 20 degrees C. Contrary to expectations, the biosensor showed narrow pH and temperature optimums. The effects of enzyme loading and type of mediator were also investigated. The biosensor showed a linear response up to 500 microM phenol.