Surface functionalisation of nanoparticles and their biological applications

Abstract

CHAPTER 1: INTRODUCTION This chapter is an introduction to the research work presented in this thesis. It begins with a bird‟s eye view of the field of nanoscience and nanotechnology, covering from its history to the latest development. The chapter proceeds to describe surface functionalisation and its importance, different types of functionalisation and its applications in biology. CHAPTER 2: EXPERIMENTAL PROCEDURES This chapter comprises of an overview of all the techniques used in this thesis work, their principle, instrument and working specifications and their uses. CHAPTER 3: PART I- FUNCTIONAILSATION OF GOLD NANOPARTICLES WITH ANTIBIOTICS; PART II- IRON OXIDE NANOPARTICLES AS ENZYMATIC BIOSENSORS Recently, we reported a novel synthesis route where we used an antibiotic cephalexin to reduce chloroauric acid. In this method colloidal gold capped by antibiotic in aqueous solution is readily prepared by a facile one-pot protocol. We have shown by a detailed investigation based on nuclear magnetic resonance and X-ray photoemission spectroscopy results, that the sulfur moiety present in the beta lactam is responsible for the dual role of reducing and capping (stabilizing) the gold nanoparticles. Interestingly, in this method, we could control the morphology of the gold nanoparticles from quasi-spherical to flat triangular flakes and finally to truncated triangles and hexagons by increasing the concentration of gold ions correspondingly. In yet another remarkable result in our earlier study, the transmission electron micrograph also showed the presence of a large number of smaller 1-3 nm particles.