NaOH induced oxygen deficiency for fluorescent SrVO3-x perovskite and its application in glucose detection

Abstract

We report a low-temperature annealing method to induce fluorescent traits in SrVO3 for the first time. The lateral two-dimensional nanomaterial was synthesized in presence of NaOH to induce oxygen deficient surface defects, thus resulting in generation of excitons. It is found that NaOH can intercalate to the crystal structure during pre-annealing homogenization, and de-intercalate while annealing, consequently creating voids on the surface to form SrVO3-x. NaOH is also seen to stabilize the B-site metal cation at a higher oxidation state V4+, that contributes to the emission at 540 nm in the visible spectrum. Owing to its oxygen deficient structure, the aqueous dispersion of as-synthesized SrVO3-x nanosheets was seen to be stable at room temperature. To further enhance its optical characteristics and aqueous stability, we doped Zn on the surface of the nanosheets. Further to this, hydrogen peroxide mediated oxidation of SrVO3-x nanosheets resulted in fluorescence quenching at emission maxima. Based on the quenching attribute of the nanosheets, we demonstrate a sensitive detection of glucose molecule in an aqueous as well as biological fluid spiked solutions. A remarkable 15 nM limit of detection in an aqueous medium makes this material highly responsive to the trace amounts of glucose. The robust optical properties of SrVO3-x nanomaterials exhibit huge potential for further investigation towards real-time monitoring soft-bioelectronics applications.