Preparation of carbon quantum dots/polyaniline nanocomposite: Towards highly sensitive detection of picric acid

Heba M Ahmed; Mohsen Ghali; Waheed Zahra; Mohamad M Ayad

doi:10.1016/j.saa.2021.119967

Preparation of carbon quantum dots/polyaniline nanocomposite: Towards highly sensitive detection of picric acid

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Nov 5:260:119967. doi: 10.1016/j.saa.2021.119967. Epub 2021 May 19.

Authors

Heba M Ahmed¹, Mohsen Ghali², Waheed Zahra³, Mohamad M Ayad⁴

Affiliations

¹ Basic and Applied Sciences Institute, Egypt-Japan University of Science and Technology, New Borg El-Arab 21934, Alexandria, Egypt; Polymeric Materials Research Department, Advanced Technology and New Materials Research Institute, City of Scientific Research and Technological Applications, New Borg El-Arab 21934, Alexandria, Egypt.
² Basic and Applied Sciences Institute, Egypt-Japan University of Science and Technology, New Borg El-Arab 21934, Alexandria, Egypt; Department of Physics, Faculty of Science, Kafrelsheikh University, Kafrelsheikh 33516, Egypt.
³ Basic and Applied Sciences Institute, Egypt-Japan University of Science and Technology, New Borg El-Arab 21934, Alexandria, Egypt; Department of Physics and Engineering Mathematics, Faculty of Engineering, Tanta University, Tanta 31527, Egypt.
⁴ Basic and Applied Sciences Institute, Egypt-Japan University of Science and Technology, New Borg El-Arab 21934, Alexandria, Egypt; Chemistry Department, Faculty of Science, Tanta University, Tanta 31527, Egypt. Electronic address: mohamad.ayad@ejust.edu.eg.

PMID: 34082352
DOI: 10.1016/j.saa.2021.119967

Abstract

Carbon quantum dots/polyaniline (CQDs/PANI) nanocomposite was successfully prepared by in-situ polymerization of aniline. CQDs were synthesized hydrothermally from gelatin with a diameter size of 4.2 nm and a 17% quantum yield. FTIR, UV-vis absorption, fluorescence spectrophotometer, XRD, TEM, XPS and lifetime decay were used to characterize the obtained nanocomposite. The formation of PANI revealed a high quenching effect on CQDs where the TEM images showed that the formed CQDs were greatly embedded in PANI matrix. In this study, CQDs/PANI nanocomposite was used for the detection of picric acid (PA) in the range 0.37-1.42 μM with a low detection limit (LOD) of 0.056 μM. The prepared sensor showed good enhancement and sensitivity towards PA in comparison to pristine CQDs and other nanostructured materials. The mechanism of PA detection has been studied where it was observed that PA is electrostatically interacted to the nanocomposite through - OH group of PA and the protonated PANI salt formed in CQDs/PANI nanocomposite by fluorescence resonance energy transfer applications. The proposed CQDs/PANI sensor was then utilized in real water samples and successfully determined the different amounts of PA spiked into tap water.

Keywords: Carbon quantum dots; Gelatin; Picric acid; Polyaniline; Quantum yield; Sensor.