Aquotris(benzotriazole)sulfatocopper(II).benzotriazole framework assembled on multiwalled carbon nanotubes through π-π interaction for H<inf>2</inf>O<inf>2</inf> sensing in pH 7 buffer solution

Aquotris(benzotriazole)sulfatocopper(II).benzotriazole (BTAH-Cu2+) framework was assembled (exploiting π-π interactions) on MWCNTs modified glassy carbon electrode (GCE/MWCNTs@BTAH-Cu2+) for efficient sensing of hydrogen peroxide in pH 7 phosphate buffer solution (PBS). The modified electrodes showed stable and well-defined surface confined redox peak at an apparent electrode potential, Eo’ = −182 mV vs. Ag/AgCl with surface excess value of 5.519 nmol cm−2. Structural, physicochemical and electrochemical characterizations of modified electrodes by single crystal XRD, FESEM, Raman spectroscopy, FTIR, QCM and control electrochemical experiments revealed the crystal structure of BTAH-Cu2+ and it’s adsorption on MWCNTs. Highly redox active GCE/MWCNTs@BTAH-Cu2+ showed excellent H2O2 sensing in comparison to GCE/BTAH-Cu2+ in pH 7 PBS highlighting the importance of MWCNTs. Amperometric i-t sensing of H2O2 on MWCNTs@BTAH-Cu2+ revealed suitability of this sensor for the linear range, 20–200 μM. The sensitivity and detection limit values are 0.153 A M−1 cm−2 and 3.3 μM respectively. Koutecky-Lévich analysis of H2O2 reduction reaction on GCE/MWCNTs@BTAH-Cu2+ confirms the two electron reduction reaction of H2O2. The ability of the MWCNTs@BTAH-Cu2+ for routine analyses was demonstrated by employing this sensor for H2O2 detection in commercial cosmetic samples.