No abstract

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.

Nanomaterials are promising in the field of optical sensors due to their unique properties. Emeraldine base of polyaniline (Nano EB-PANI) was prepared, characterized and applied as an optical formaldehyde sensor. FTIR data confirm the formation of the EB-PANI. TEM and SEM revealed the size and shape of the nanoscale EB-PANI. XRD showed that the obtained nano EB-PANI has a partial crystalline nature. The sensing mechanism is based on the reaction of formaldehyde with Nano EB-PANI- to form a complex as described by molecular modeling HF/3-21G** level of theory. Results showed that Nano EB-PANI- detect low concentrations of formaldehyde ranging from 0.0003 to 0.9 ppm in a dose-dependent manner. The molecular modeling theory analysis showed that formaldehyde could interact with the amine of EB-PANI in, ring 3 or 4 or both together. The binding energy and dipole moment of the interaction between formaldehyde and polyaniline nanosensor were calculated by HF/3-21g** level of theory. The interaction with ring 3-NH gives a less stable product with a high dipole moment 6.978 Debye comparing with 1.678 Debye for the product of formaldehyde interaction with the terminal ring 4-NH. The development of such novel EB-PANI nanosensor can be used as, reliable and sensitive formaldehyde sensor.