Non-enzymatic amperometric sensor of catechol and hydroquinone using Pt-Au-organosilica@chitosan composites modified electrode

An amperometric non-enzymatic sensor based on Pt-Au-organosilica@chitosan (Pt-Au-OSi@CS) composites has been developed for determining catechol (CC, 1,2-dihydroxybenzene) and hydroquinone (HQ 1,4-dihydroxybenzene). The Pt-Au-OSi@CS composites were synthesized using positively charged inorganic-organic core-shell organosilica@chitosan (OSi@CS) crosslinked nanospheres as templates for the assembly of negatively charged 1-3 nm Au nanoparticles seeds which acted in subsequent step as nucleation sites for the reduction of platinum. Due to the excellent electrocatalytic response of Pt-Au-OSi@CS for the reduction of CC and HQ the sensor based on the Pt-Au-OSi@CS exhibited broad linear range of 0.06-90.98 mu for CC and 0.03-172.98 mu M for HQ. The low detection limits of 0.02 and 0.01 mu M (S/N = 3) were obtained for CC and HQ respectively. The operational conditions were optimized. The sensitivities of the non-enzyme electrode for CC and HQ were 307.95 mu A mM(-1) cm(-2) and 1714.20 mu A mM(-1) cm(-2), respectively. (C) 2012 Elsevier B.V. All rights reserved.