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Phenothiazine‐Capped Gold Nanoparticles: Photochemically Assisted Synthesis and Application in Electrosensing of Phosphate Ions
Author(s) -
Gupta Sandeep,
Singh Akhilesh K.,
Jain Ravish K.,
Chandra Ramesh,
Prakash Rajiv
Publication year - 2014
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201300212
Subject(s) - colloidal gold , phenothiazine , amperometry , electrochemistry , electron transfer , cyclic voltammetry , inorganic chemistry , ion , chemistry , electrode , nanoparticle , detection limit , photochemistry , materials science , nanotechnology , organic chemistry , medicine , chromatography , pharmacology
We describe a green photochemical route for the synthesis of gold nanoparticles (AuNPs) using phenothiazine (PTZH) as a reductant as well as a stabilizer without any extra control (i.e. surfactant, pH, etc.). The synthesized AuNPs are characterized by using UV/Vis spectroscopy, cyclic voltammetry, and transmission electron microscopy. Furthermore, a possible mechanism for the formation of the AuNPs is proposed. This hybrid electrode material, derived from nanoscale gold particles capped with PTZH and its oxidation product, is explored for the development of a highly sensitive amperometric sensor for phosphate ions. The electrochemistry behind the electrocatalytic sensing of phosphate is attributed to the nano‐sized gold particles that are capped with PTZH and its oxidation product, which exhibit high electron‐transfer kinetics through the interaction of the hybrid PTZH–AuNPs with oxygen atoms of ${{\rm{PO}}_4^{3 - } }$ . The modified electrode efficiently gives an electrochemical signature of phosphate ions at a potential of −0.336 V versus AgCl/Ag and shows a linear response toward phosphate sensing, with a sensitivity of 0.794 μA μ M −1 and a limit of detection of 0.022 μ m, at a signal‐to‐noise ratio of 3.