Laccase immobilized onto graphene oxide nanosheets and electrodeposited gold–cetyltrimethylammonium bromide complex to fabricate a novel catechol biosensor

In this study, a new biosensor is developed with reliable and easy-to-use biodevice properties for catechol determination in real samples. A method is proposed for the fabrication of biosensors to sense catechol based on the adsorption method of laccase immobilization. Hence, a glassy carbon electrode was modified via graphene oxide nanosheets and then it was modified with a gold–cetyltrimethylammonium bromide nanocomposite to adsorb and immobilize laccase on the electrode surface. The results showed laccase immobilization onto the reformed glassy carbon electrode, and a direct electron transfer reaction between laccase and the electrode. The mechanism of electron transferring was $$\hbox {EC}^\prime $$ . Also, $$k_{\mathrm{s}}$$ and $$\alpha $$ were calculated as $$0.41\, \hbox {s}^-1$$ and 0.33, respectively. For this biosensor two linear ranges, $$0.1\times 10^-6$$ to $$5\times 10^-6$$ M and $$16.7\times 10^-6$$ to $$166\times 10^-6$$ M, and a detection limit of $$1.5\times 10^-6$$ M were obtained.