Effect of Gold/Amine Nanoparticles on Polyaniline Electrochemical Sensitivity to Formaldehyde.

BACKGROUND: Nanoparticles have a promising potential in electrochemical sensitivity. Polyaniline (PANI) received significant attention in the latest years owing to its high conductivity and excellent electrochemical stability. This research aims to study the effect of gold nanoparticles capped octadecyl amine (Au/ODA) on polyaniline emeraldine salt (ES) electrochemical sensitivity to formaldehyde (FA) using DPV technique. Furthermore, ES and Au-ODA/ES have been applied for the first time in sensing FA. Few relevant patents to the topic have been reviewed and cited in this article.

METHODS: Emeraldine salt (ES) was prepared by doping the prepared emeraldine base (EB) powder with dodecylbenzene sulfonic acid (DBSA) at a ratio of 1:2 W/W. Then ES-DBSA was dissolved in chloroform solution and added to Au/ODA nanoparticles solution to obtain Au/ES-DBSA nanocomposite. FA sensors were prepared by depositing a film from ESDBSA or Au/ES-DBSA on a working electrode and the potential was measured at FA different concentrations in Electrochemical cell kit.

RESULTS: FTIR and XRD confirmed the structure of ES-DBSA and Au/ES-DBSA. The obtained results reveal that the ESDBSA nanosensor is an efficient sensor because it can recognize the low levels of FA starting from 0.06 ppm. The recorded electrochemical oxidation current shows a linear direct relationship between the produced current and FA concentration in case of ES-DBSA nanoparticles while it illustrates a fluctuating signal with lower sensitivity in the case of the novel prepared nanocomposites (Au/ES-DBSA). This may be due to the gold capping agent (ODA), which in turn could inhibit the role of DBSA and decrease the conductivity of the nanocomposite.

CONCLUSION: Herein we described the application of ES-DBSA and Au/ES-DBSA nanocomposite for the first time as a novel, facile, and cheap method for electrochemical sensitive detection of formaldehyde. The gold capping agent ODA hinders the ES-DBSA conductivity through interaction with the DBSA sulfo group.