A novel electrochemical aptasensor for highly sensitive and quantitative detection of the streptomycin antibiotic

In the present study, we report a facile approach to employ gold nanoparticle (AuNPs) and thiol graphene quantum dots (GQD-SH) as the nanomaterial for ultrasensitive detection of streptomycin (STR). Based on this strategy, a GQD-SH was immobilized onto the surface of a glassy carbon electrode (GCE). AuNPs have been immobilized on SH groups of GQDs through bonding formation of AuS and Apt have been loaded on the electrode surface through the interaction between thiol group of aptamer. By incubating STR as a target onto the surface of the prepared Apt/AuNPs/GQD-SH/GCE as a proposed nanoaptasensor, the Apt/STR complex was formed and the changes of the electrochemical signal were evaluated with the EIS technique. The proposed nanoaptasensor showed wide linear range from 0.1 to 700pgml−1. Finally, the proposed nanoaptasensor was successfully applied for the determination of STR in real samples and satisfactory results were obtained. •AuNPs/GQD-SH as nanocomposite was employed for attachment of Apt onto the GCE.•K3Fe(CN)6/K4Fe(CN)6 was used as the redox probe and EIS as analytical technique.•The aptasensor showed high sensitivity and selectivity for the detection of STR.•This aptasensor demonstrated a linear response with STR and LOD in the pg/ml−1 range.