Effective modified electrode of poly (1-naphthylamine) nanoglobules for ultra-high sensitive ethanol chemical sensor

Poly (1-naphthylamine, PNA) nanoglobules, an analog of polyaniline (PANI), were synthesized by facile chemical polymerization of 1-naphthylamine monomer in the presence of HClO₄ and cupric chloride (CuCl₂). The as-synthesized PNA nanoglobules were characterized in terms of their morphological, compositional, structural, optical and sensing properties. The morphological observations revealed that the synthesized PNA were grown in high density and possessed nanoglobular shape with the average diameter of ~300-400nm. The FTIR and Raman scattering studies deduced the formation of PNA upon the polymerization of 1-naphthylamine monomer. Electrochemical studies suggested the rapid sensing response through high electrocatalytic activity over the surface of PNA nanoglobules modified electrode. The synthesized PNA nanoglobules were efficiently applied as an electron mediator for the fabrication of high-sensitive chemical sensor towards the detection of ethanol in aqueous medium. The fabricated ethanol chemical sensor based on PNA nanoglobules exhibited a high and reproducible sensitivity of ~1.66μAmM^-1cm^-2 with a response time 10s. The obtained linear dynamic range (LDR) for the fabricated PNA nanoglobules based chemical sensor was from 0.78mM to 50mM with the correlation efficient of R=~0.965.