The existence of nanomaterials is a revolutionizing step towards the fabrication of nanodevices and it enhances the enthusiasm of the researchers for the development of new devices with improved performance relative to that of bulk material based devices. Among the nanomaterials, the metal oxide nanostructures have drawn the attention of scientific community in the development of different biochemical and biomedical nanodevices in the recent time. Today, the nanotechnology based applications of several materials particularly biosensing, molecular imaging, biological separation, biomarkers and photodynamic therapy have given wide spectrum of the fabrication of novel and sensitive nanodevices. The attraction of nanomaterials based devices is hidden in the fact of their desirable and unique properties such as high surface to volume ratio, biocompatibility, fast electron transfer rate, and nontoxic in many cases. The biocompatibility is the most favourable property of several nanomaterials such as ZnO, TiO2 etc. which provide the solid platform for the synthesis of nanomedicine. In the sensor technology, the uses of nanomaterials have shown the drastic and bombastic realization of high sensitivity for a particular sensor and the possible detection of specific analytes from their small volumes. The metal oxide nanostructures show a fast electron communication, and high degree of adsorption of biosensitive material which further enhances the sensitivity of nanosensor device. The metal oxides nanostructures  exhibit tuneable size; morphology based chemical and physical properties which are easily to combine with biosensitive material in the fabrication of sensitive chemical and biosensors. The metal oxide nanostructures experienced attractive surface chemistry, high surface  to volume ratio, valuable thermal and electrical properties, therefore the development of nanosensors is accompanied by high sensitivity, low limit of detection and a fast response time.

In this dissertation, several metal oxide nanostructures have been presented such as ZnO, CuO, NiO, Co₃O₄, Fe₂O₃, Mn₃O₄, NiCo₂O₄ and TiO₂. By exploiting the favourable properties of these metal oxides for the sensing, thus have been used potentially in the fabrication of chemical nanosensors.