ABSTRACT
We have used the AT-cut quartz crystal sensor to detect hydrogen peroxide via the peroxidase catalysed oxidation of 3,3′-diaminobenzidine. The reaction produces a quartz sensor detectable signal but mainly a suspension that cannot be detected. We have used surfactants to interact with the amphiphilic oxidised products to increase their surface activity and their ability to adsorb to the crystal surface. Tween 80 exhibits optimised response effects at 0.012% (v/v) whereas Triton X-100 is optimum at 0.1% (v/v). Consequently we have improved quartz crystal sensitivity to peroxide by 8-fold in the frequency response and by 3-fold in the series resonance impedance. Anionic and cationic surfactants tend to inhibit the crystal response.
