Construction of a sensitive electrochemical sensor based on 1T-MoS2 nanosheets decorated with shape-controlled gold nanostructures for the voltammetric determination of doxorubicin

An innovative and portable design to fabricate an electrochemical sensor based on metallic phase MoS2 (1T-MoS2) decorated with shape-dependent gold nanostructures for the determination of doxorubicin (DOX) is presented. In this context, homogenous and uniform single-crystal gold nanospheres (AuNSPs) and nanorods (AuNRDs) were firstly synthesized by seeded growth approach. Afterwards, AuNSPs and AuNRDs were anchored on 1T-MoS2 surfaces to construct the desired electrochemical sensing platform towards the DOX assay. 1T-MoS2 was exfoliated by metal intercalation process using NaK metal alloys. The structure and surface morphology of 1T-MoS2, AuNSPs, and AuNRDs were characterized by XPS, Raman, UV-vis, TEM, and SEM. The electrochemical behavior of DOX using various MoS2-based electrochemical sensors prepared on screen-printed electrode (SPE) was examined by cyclic voltammetry and adsorptive stripping differential pulse voltammetry. The electrocatalytic efficiency of AuNRDs on 1T-MoS2 was also compared with that of AuNSPs on 1T-MoS2, and it showed much better electrocatalytic activity towards the DOX. A nanocomposite prepared with AuNRDs and 1T-MoS2 on SPE (AuNRDs/1T-MoS2/SPE) exhibited a linear relationship between peak current and DOX concentration in the range 0.01–9.5 μM with a detection limit of 2.5 nM. The AuNRDs/1T-MoS2/SPE was successfully applied to the sensitive and rapid determination of DOX in spiked human serum samples with satisfactory recoveries in the range 99.2–100.8%.