Preparation and characterization of carbon quantum dot‐hydroxyapatite‐alginate based hybrid fluorescent ink for sensor application

Abstract

AbstractDevelopment of multifunctional fluorescent inks is gaining attention owing to the current technological developments in optoelectronics. The present work involves the development of a simple and highly fluorescent carbon quantum dot (CQD)‐based nano‐ink suitable for sensor and bioimaging applications. CQDs were synthesized by a one‐pot hydrothermal method using folic acid (FA) a carbon source. The synthesized CQDs were conjugated with hydroxyapatite (HAP) and sodium aliginate (SA) by covalent and ionic linkages methods. Fourier transform infrared (FT‐IR) spectra confirm the formation of nano‐inks by the ionic interaction between the HAP and SA and  conjugation with CQDs through hydrogen bonding. The surface morphology of the CQDs and nano‐inks depicts that the particles exhibit in spherical and needle‐like morphological structures, respectively. The X‐ray diffraction (XRD) pattern confirms that the obtained CQDs and fluorescent nano‐ink are highly crystalline in nature. The SA and HAP provided shear thinning ability and structural stability for the fluorescent nano‐ink. The nano‐ink‐based strips displayed high fluorescence under Ultraviolet irradiation. The fluorescent nano‐ink could be used in bioimaging, flourescent coatings, and anti‐counterfeiting applications.