Carbon Nanomaterials for Bioimaging, Bioanalysis, and Therapy

1 Introduction to Carbon Structures

Meng‐Chih Su¹ and Yuen Yung Hui²

¹ Department of Chemistry, Sonoma State University, California, USA

² Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan

1.1 Carbon Age

Welcome to the Carbon World!

It seems that we already know the chemistry of carbon quite well, mostly in the form of graphite, through its long association with humans in history. Carbon is a simple element, predominantly (99% natural abundance of C‐12) containing the same number (6) of protons and neutrons, and therefore is radioactively stable. Of its other isotopes, C‐13 (1%) and C‐14 (<100 ppm), only C‐14 is radioactive with half‐life time lasting for a long 5730 year. It has been used routinely for the chronological tracking in archeology. With its relatively low mass, carbon is in the sixth place of all the hundred plus elements known today with an atomic number of Z = 6.

In nature, carbon ranks as the fourth element of cosmic abundance, after hydrogen, helium, and oxygen, and counts for about 20% by weight of all livestock and humans on earth, next only to oxygen (60%). Grouped together with silicon and germanium (4A group) in the Periodic Table of Elements, the chemical reactivity of elemental carbon may be considered inert compared to the neighboring nitrogen (5A) and oxygen (6A) groups because of its thermodynamic stability. Hence, graphite solid is used as a reference state for just about all thermodynamic measurements and ...