Development of Stimuli-Responsive Self-Assembled Materials for Biomolecular Applications

Abstract

The thesis entitled ‘‘Development of Stimuli-Responsive Self-Assembled Materials for Biomolecular Applications’’ deals with the design, synthesis, and characterisation of low molecular weight hydrogel systems as well as small molecular probes and their responses towards various stimuli. Depending upon the nature of their association, the present work has been divided into two main subsections.

Chapter 1 presents an overview of the general area of the low molecular weight hydrogel and stimuli-responsive hydrogel, different types of gelator molecules, their self-assembly patterns, along with applications of the LMOGs hydrogels.

Chapter 2A deals with the synthesis of pyrene-based monosaccharides namely D-gluconic acid and glucose and their gelation propensity. Selective gelation of pyrene linked gluconic acid-based amphiphilic compound, both in aqueous medium and EtOH. Further, the gelator was utilized to differentiate between alcoholic and non-alcoholic beverages and the sensing of insulin.

Chapter 2B describes the synthesis and self-assembly properties of two different pyrene-disaccharide compounds (with maltose and lactose) in an aqueous medium. Lactose based Hydrogel is successfully utilized for studying the sustainable release of anticancer drugs, such as Doxorubicin (DOX) and mitoxantrone (MT). In addition, lactose-based amphiphile also showed specific interaction with Cholera Toxin B (CTB).

Chapter 3A. describes the self-assembly studies as well as hydrogelation of a tyrosine-functionalized low molecular weight pyrenyl probe (L-PyTyrOH) in a buffered medium (pH 7.4). Then lanthanide ion (Eu3+) is doped into the hydrogel network and the resultant metallogel is used for the detection of pathogenic biomarkers such as dipicolinic (DPA) acid and phytic acid at physiological pH.

Chapter 3B describes the formation of a two-component ‘charge transfer’ (CT) hydrogel system, comprising of a pyrene-amino acid conjugate and a 4-Chloro-7-nitrobenzofurazan (NBD) derivative in 1:1 molar ratio. CT gel was used for the ‘Turn-on’ sensing (cyan emission) of the biogenic amino acids, namely cysteine and homocysteine Chapter 4A. describes the design and self-assembly studies of the pyrene-based amphiphilic compounds having different amino acids residues at the terminal position, such as histidine and tryptophan. Moreover, the present system was also used for detecting the α-chymotrypsin in a human blood serum sample Chapter 4B. describes the synthesis and self-assembly studies of the of gallate attached pyrenyl derivatives connected via aromatic amino acid namely phenylalanine and tyrosine. The hydrogels were then involved in designing sensor array for Cu2+, Hg2+, and Fe3+ and selective sensing of hypochlorite Chapter 4C. deals with the studies of different hydrogel-nanocomposite hybrid materials where graphene oxide has been involved as carbon nanomaterial. The hybrid hydrogels are utilized for the removal of organic dye namely methylene Blue (MB) and rhodamine B (RhB) from the aqueous solution and spermine estimation. Chapter 5A presents the design and synthesis of a ruthenium complex-based charge transfer probe and its application in selective detection of Spodoptera Litura Nuclear Polyhedrosis Virus (SLNPV). Chapter 5B describes the ratiometric sensing of the Spilosoma Obliqua Nuclear Polyhedrosis Virus (SONPV) by acetyl ester derivative of pyranine dye.