Chitosan is partially deacetylated chitin, resulting in some glucosamine in the polymer. The primary amine can be labeled with a fluorescent amine-reactive dye. the cheapest probably being FITC (fluorescein isothiocyanate). There is precedent for this:

https://www.sciencedirect.com/science/article/abs/pii/S1872204007600152

Other dyes are better for confocal microscopy because they are less prone to photobleaching. A rich resource for amine-reactive fluorophores can be found here:

https://www.thermofisher.com/us/en/home/references/molecular-probes-the-handbook/fluorophores-and-their-amine-reactive-derivatives.html

Labeling may be tricky because chitosan solubility is better at acidic pH, whereas labeling works better at slightly alkaline pH. Also, labeling will influence the physical properties of the chitosan, so keep the labeling stoichiometry to a minimum.

Hello,

I suggest you to check this article:- Fluorescent labeling of chitosan for use in non-invasive monitoring of degradation in tissue engineering (Journal of Tissue Engineering and Regenerative Medicine 2013, 7(1):39–50)

Thanks a lot everyone. Will definately get back to you all once I try some samples. Thanks again.

The fluorescent chitosan nanoparticles (FCNP) could be obtained by the reaction between the isothiocyanate group of fluorescein isothiocyanate and the primary amine group of the D-glucosamine residue

Please see this work as well to synthesis fluorinated chitosan

Fluorinated Chitosan To Enhance Transmucosal Delivery of Sonosensitizer-Conjugated Catalase for Sonodynamic Bladder Cancer Treatment Post-intravesical Instillation

Article Fluorinated Chitosan to Enhance Transmucosal Delivery of Son...