A novel electrochemical sensing platform based on mono-dispersed gold nanorods modified graphene for the sensitive determination of topotecan

In this research, we developed a novel design to fabricate a sensitive and selective electrochemical sensor based on high-quality graphene decorated with mono-dispersed gold nanorods (AuNRDs) for the determination of topotecan (TPC) in human blood serum. For this purpose, the screen-printed electrode (SPE) was firstly modified with graphene prepared by metal intercalation process (MI-GR), and then followed by the decoration of mono-dispersed AuNRDs synthesized by seed mediated growth method. The synthesized MI-GR and AuNRDs samples were characterized by Raman, XPS, UV-Vis and TEM techniques. Electrochemical studies indicated that the electrocatalytic activity of MI-GR has superior than that of chemically reduced graphene (CR-GR) prepared by conventional approach due to its faster electron transfer ability. Moreover, AuNRDs/MI-GR modified SPE (AuNRDs/MI-GR/SPE) demonstrated a wide linearity in the range of 0.1 - 16.0 mu M with a low detection limit of 22.0 nM. The analytical reliability of AuNRDs/MI-GR/SPE was successfully confirmed by the detection of TPC in human blood serum with the satisfactory recoveries at the range of 99.8-100.07%. AuNRDs/MI-GR/SPE could be utilized as an alternative analytical tool for the determination of anti-cancer agents such as TPC in the next generation clinical applications.