Electrochemical aptasensor for detection of copper based on a reagentless signal-on architecture and amplification by gold nanoparticles

A highly sensitive and specific electrochemical aptasensor for Cu2+ detection based on gold nanoparticles (AuNPs) is presented. In this work, AuNPs offered a big surface area to immobilize a large number of aptamers and excellent electrochemical signal transduction. Its high sensitivity, low detection limit, and wide detection range are the main advantages over our former copper aptasensor. The peak current increased proportionally to the Cu2+ concentration over the range from 0.1 nM to 10 μM with a detection limit of 0.1 pM. The presence of other divalent metal ions did not affect the detection of Cu2+, which indicates a high specificity of Cu2+ detection could be detected. Rapidity, simplicity, and excellent selectivity make it suitable for practical use in determination of Cu2+ from lake samples.