In this project, we synthesize various kinds of nanoparticles and nanostructures for sensing and spectroscopic applications. Various synthesis routes such as hydrothermal, co-precipitation method, microwave synthesis etc. have been used with success to prepared different kinds of nanoparticles such as quantum dots, carbon dots upconversion nanoparticles, carbon dots, metal-organic frame works, thin films etc [1-18]. The utility of the quantum dots for the sensitive and selective detection of mercury has already been demonstrated [1-2]. In addition, the upconversion nanoparticles are prepared for the future bio-imaging applications [4-8] . The synthesis conditions as well as experimental conditions are tailored to probe the influence of co-dopant, excitation laser power density, post-annealing temperature etc., on the luminescence emission properties of the upconversion nanoparticles [2-3]. Further, we prepared nanoporous alumina using the electrochemical route and investigated the influence of electrolyte composition on the photoluminescence as well as the pore arrangement on nanoporous alumina [9-11]. Along with it, we utilize the home-made flexible nanostructures and nanoparticles for sensing applications by integrating with spectroscopic tools such as Raman Spectroscopy, Fluorescence spectroscopy etc. Recently, we have developed substrates for Raman Spectroscopy. Such substrates facilitate femtomolar detection of analyte molecules by exploiting the concentration enrichment due to superhydrophobicity and the plasmonic signal enhancement due to silver nanoparticles [12]. The applications of these particles for Nanobioimaging and sensing is demonstrated our recent works [13-18]