Near InfraRed (NIR) nanoemitters for bioimaging applications
FakultätenFakultät für Naturwissenschaften
This thesis focuses on the preparation of two types of multifunctional NIR emitting fluorescent nanoprobes, ultrasmall gold nanoparticles and fluorescent nanodiamonds (FNDs). To stabilise the NIR emitting nanoparticles by polymer coating, multifunctional biocompatible polypeptide copolymers with different lengths, different charge of the polypeptide backbone chains have been prepared from native proteins or modified globular proteins using "denaturation and pegylation" strategy. These polypeptide copolymers have several attractive features, such as monodispersity, biocompatibility, non toxicity and most importantly the protein backbone contain various functional groups (-COOH, -NH2, -OH) along the polymer backbone which allow the attachment of biomolecules to the polymer using very simple conjugation chemistry. Thioctic acid (TA) functionalised polypeptide copolymers were used to stabilise NIR emitting ultrasmall AuNPs by following a one step synthetic procedure. dcBSA-PEO(5000)28-(TA)26 stabilised AuNPs are well uptaken by the A549 cell line and they were located at the perinuclear region. Further nuclear localised signal (NLS) functionalised NIR emitting AuNPs were developed that can not only cross the cell membrane but also can penetrate through the cell nucleus membrane. This thesis also deals with another type of NIR fluorescent nanoparticles, called fluorescent nanodiamonds (FNDs). The high tendency of FNDs to form aggregates and colloidal instability after chemical modification, were overcomed by coating the FNDs with cationised bovine serum albumin (cBSA) derived copolymer by non-covalent interactions. Finally, the magneto metric sensing of biologically important external spins using FNDs has been demonstrated. Iron storage protein ferritin has been introduced at the FNDs surface by non-covalent interactions and detected by measuring changes in the relaxation time (T1) and decoherence rate (T2) of FNDs.
Erstellung / Fertigstellung
Normierte SchlagwörterNanostrukturiertes Material [GND]
Multifunctional materials and devices [LCSH]