The stability of the biosensor was attempted to be improved by adding BSA into sensor mixture at concentrations up to 5% (w/v). There was about a 40% increase in colour development for 5% BSA addition (Figure 5(a)). However, the negative controls with no enzyme exhibited slight yellow colour formation (approximately 10%). This nonspecific background reaction may be due to the sulfide moieties in BSA, and DTNB might be reacting and forming colour. The background colour development in control sensors can be confusing especially in visual determination. Thus it was concluded that BSA could not be used as an enzyme stabilizer in this biosensor development study. Next, effect of glucose on the stability of the biosensor was tested up to 15% (w/v) concentrations. It was found that glucose increased biosensor colour development by about 35% for 15% glucose addition (Figure 5(c)). There was no colour development in control sensors with the addition of glucose.