Abstract
A metal-free catalyst is described that consists of a composite that can be prepared from mesoporous carbon spheres (MCS) and graphene oxide (GO) under mild aqueous synthetic conditions. The reduced graphene oxide (rGO) sheets tend to aggregate, but due to the insertion of MCS, the aggregation is prevented. This leads to a larger surface area and more adsorption sites for the cancer drug doxorubicin (DOX). The pi-interaction between DOX and rGO is also beneficial for the adsorption of DOX. A glassy carbon electrode (GCE) was modified with the composite and used to detect low levels of DOX, typically at a peak potential near -0.45 V (vs. Ag/AgCl). The modified GCE has a wide linear response range (10 nM - 10 mu M), a low limit of detection (1.5 nM; at S/N = 3), excellent selectivity, long-term storage stability and reproducibility. It was applied to the determination of DOX in spiked serum where it gave reliable results.
Graphical abstract Schematic representation of the preparation of mesoporous carbon spheres/reduced graphene oxide (MCS/rGO) sample, and the CV scan of doxorubicin (DOX) on MCS/rGO based nanoprode.