Quantum dot-based security ink and fluorescent flexible films

Quantum dot-based security ink and fluorescent flexible films: Preparation, characterization, and applications to multiple anti-counterfeiting and cell imaging

Colorless or light-colored quantum dots show strong resistance to photo-bleaching, tunable emission properties under various excitations, colloidal stability, and bio-compatible nature. Owing to these properties, these are widely used in fluorescence sensing, biological imaging, biomarkers, and anti-counterfeiting applications. Counterfeiting of valuable items viz., confidential documents, currency and jewelry became the global problem. Surface modification and quantum confinement of quantum dots with various stabilizing agents help in tuning their required properties for anti-counterfeiting and luminescent probe applications. This chapter provides comprehensive explanation about the preparation techniques for quantum dots, crystal field parameters, morphological, and optical band tuning requirements along with the compositional stability of quantum dots both in ink and thin film forms. We analyze the biologically relevant properties of quantum dots focusing on the following topics: quantum dot surface treatment and stability, labeling of cellular structures and receptors with quantum dots, incorporation of quantum dots in living cells, cytotoxicity of quantum dots and influence of the biological environment on the biological and optical properties of quantum dots. The chapter concludes with the present technology of using quantum dots to prevent counterfeiting and bio-imaging applications. Finally, this chapter provides an analysis of the prospects of application of quantum dots in selected important areas of anti-counterfeiting and bio-imaging.

Source : Quantum Dots - Emerging Materials for Versatile Applications

Link : https://www.sciencedirect.com/science/article/pii/B9780323852784000143