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Zinc oxide (ZnO) is a semiconductor metal oxide nanoparticle with inherent optical properties. Among the different zinc oxide nanostructures, nanoflowers have greater surface area. Utilizing this property a reagentless biosensor has been developed for the detection of beta amyloids, a hallmark of neurodegenerative diseases like Alzheimer's disease, Creutzfeldt-Jakob Syndrome, insulin dependent type II diabetes etc. The poor fluorescence quantum yield and photobleaching effect of Thioflavin T (ThT) upon binding to the model insulin amyloid beta sheets in solution can be overcome by the present engineered biosensor where ThT acts as a target as well as a reporter to detect amyloids adsorbed on a solid template based on ZnO nanoflower. ThT was adsorbed on ZnO NFs grown over nano-silver thin film coated glass slide. The in vivo imaging system was used to detect and quantify the fluorescence intensity generated from the substrates upon binding with insulin amyloid. ZnO NFs have the waveguiding property which increases the local field intensity caused by a resonance between the guided fundamental mode and evanescent field associated with high- order modes. This resonance phenomenon reinforces the excitation of the fluorophores in close proximity of the NFs thereby exhibiting enhanced fluorescence like Fabry Pero't Resonator (FPR). Considering the engineering and sensitivity, the reported nanobiosensor developed on ZnO nanoflower can be treated as faster and cost effective amyloid sensor. [ABSTRACT FROM AUTHOR]

An electrokinetic potential (ζ-potential) based approach was introduced to address the amyloid degradation on ZnO-nanoflower platform. The hallmark of neurodegenerative disorders like Alzheimer's disease, Parkinson's disease (PD), Creutzfeldt-Jakob Disease (CJD), Prion- associated diseases, type-II diabetes, etc. is the deposition of misfolded protein aggregates predominantly β-sheeted in structure and fibrillar morphology, known as amyloids, in the brain and different parts of the body. Agents that can degrade these amyloids can be potential candidate for the therapy of amyloidosis. Ultrasmall nanoparticles are gaining interest due to their ability to cross blood brain barrier (BBB) which is favorable for the treatment of neurodegenerative disorders. Considering the influence of Zn2+ in the formation of Aβ aggregates instead of fibrillation, the present study was designed based on the ZnO nanoparticles (ZnO-NP) and ZnO nanoflowers (ZnO-NF) to compare the anti amyloid ability using a model huminsulin amyloid. Fluorescence study, atomic force microscopy (AFM), IR spectroscopy (FTIR) and reduction of fibril size using dynamic light scattering showed that ZnO-NF can degrade amyloids with a higher capacity than their nanoparticle counterpart. Significant reduction in magnitude of ζ-potential in ZnO-NF treated huminsulin amyloid supported the notion to come to the consensus and became the new indicator for anti-amyloidosis. The cell viability assay of ZnO-NP and ZnO-NF at a higher dose than that used for amyloid degradation using PC12 and HaCaT cell lines showed their biocompatibility in a safe manner. Thus, it can be suggested that ZnO-NF would be a better candidate for amyloid degradation compared to ZnO-NPs due to higher surface to volume ratio of the petals. Unlabelled Image • Amyloidosis requires degradation of amyloids as a potential therapy. • Agents that can degrade amyloids are potential drug candidates. • Zinc oxide nanoflower (ZnO-NF) structure was exploited to dissociate insulin amyloids in vitro. • A decrease in ζ-potential magnitude was used as a parameter for anti amyloid activity. • The engineered ZnO-NF was found to be non toxic. [ABSTRACT FROM AUTHOR]