Chapter 8 - Fundamental photophysical properties of fluorescent carbon dots and their applications in metal ion sensing and bioimaging

Abstract

Fluorescent carbon dot (CD) has emerged as a prominent alternative of conventional heavy metal semiconductor nanoprobe (quantum dot), organic dye, and fluorescent protein for versatile applications. Primary focus of this chapter is on application of fluorescent CD as intracellular imaging probe and metal ion sensor. Facile synthesis technique, easy surface functionalization, bright and tunable fluorescence property, nonmetallic carbon-based structure, biocompatibility, and low cytotoxicity are the key features of fluorescent carbon nanoparticles (CP). Briefly, CPs with <10nm size with bright and tunable fluorescence property in green/red/near infrared region are suitable for metal ion sensing and intracellular bioimaging probe. This chapter will demonstrate a brief survey on chemical design of functional CD-based probe, origin of fluorescence property, and their influence in potential application for bioimaging (in-vitro and in-vivo) and heavy metal ion sensing. Intracellular imaging will include imaging of subcellular organelle like nucleus, nucleolus and mitochondria, cellular RNA, glutathione level, etc. On the other hand, sensing of heavy metal ions will cover those metals which are detrimental to human health even in trace amounts like Hg(II), Cd(II), Pb(II), etc.