Probing cysteine self-assembled monolayers over gold nanoparticles - Towards selective electrochemical sensors

► Electrochemistry of SAMs-cysteine at gold nanoparticles is compared to that on macro-size gold. ► Au-Aunano-Cys electrode response in presence of SDS is stable due to the strong AuS bond. ► The electrode response is sensitive and stable for Dopamine detection and tertiary mixtures.