Single step synthesis of gold–amino acid composite, with the evidence of the catalytic hydrogen atom transfer (HAT) reaction, for the electrochemical recognition of Serotonin

Highlights: • A single step route for the synthesis of gold–amino acid composite using IPCF approach. • The mechanism of the synthesis process has been nicely elucidated. • The composite formation mechanism is supported by the PCET reaction. • The composite material performed as an electro-catalyst for the detection of Serotonin. A composite architecture of amino acid and gold nanoparticles has been synthesized using a generic route of 'in-situ polymerization and composite formation (IPCF)' [1], [2]. The formation mechanism of the composite has been supported by a model hydrogen atom (H^• ≡H⁺+e⁻) transfer (HAT) type of reaction which belongs to the proton coupled electron transfer (PCET) mechanism. The 'gold–amino acid composite' was used as a catalyst for the electrochemical recognition of Serotonin.