Abstract

The goal of this dissertation was to develop and assess surface modifications of fluorescent nanodiamonds (NDs) for optical sensing. Three modification routes were tested, each aimed at a different application. Modification with poly-L-lysine (pLys) was verified for optical sensing of pH via an interrelationship between electrically negative (NV¯) and neutral (NV0) nitrogen-vacancy centres. Immobilisation of Ochratoxin A (OTA), one of the most common mycotoxins, was examined for optical investigation of interactions between the toxin and DNA in various comestible liquids. Attachment of hyperbranched polyglycerol (HPG) was tested for creation of a biomarker characterised by excellent colloidal stability in a broad pH range, in highly ionic environments and physiological media while maintaining a stable optical response. Moreover, the aim of the dissertation was to exploit techniques for depositing fluorescent NDs on glass structures to create composite platforms suitable for integration with modern optoelectronic systems used in magnetic field sensing. Matrix-assisted pulsed laser evaporation (MAPLE) was tested to obtain patterns of the diamond particles on glass coverslips for 3D sensing of the magnetic fields. Dip coating was examined to cover glass rods with the fluorescent diamond particles for drawing a composite fibre with the particles in its core. A microfluidic system was assembled to infuse anti-resonant hollow-core fibres (ARHCFs) with suspensions of fluorescent diamond particles to create platforms for optical sensing of magnetic field gradients.

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