Rahul Ranjan

Eco-friendly synthesis of CuInS2 and CuInS2@ZnS quantum dots and their effect on enzyme activity of lysozyme

We report on the green and facile aqueous microwave synthesis of glutathione (GSH) stabilized luminescent CuInS2 (CIS, size = 2.9 nm) and CuInS2@ZnS core–shell (CIS@ZnS, size = 3.5 nm) quantum dots (QDs). The core–shell nanostructures exhibited excellent photo- and water/buffer stability, a long photoluminescence (PL) lifetime (463 ns) and high PL quantum yield (PLQY = 26%). We have evaluated the comparative enzyme kinetics of these hydrophilic QDs by interacting them with the model enzyme lysozyme, which was probed by static and synchronous fluorescence spectroscopy. The quantification of the QD–lysozyme binding isotherm, exchange rate, and critical flocculation concentration was carried out. The core–shell QDs exhibited higher binding with lysozyme yielding a binding constant of K = 5.04 × 109 L mol−1 compared to the core-only structures (K = 6.16 × 107 L mol−1), and the main cause of binding was identified as being due to hydrophobic forces. In addition to the enzyme activity being dose dependent, it was also found that core–shell structures caused an enhancement in activity. Since binary QDs like CdSe also show a change in the lysozyme enzyme activity, therefore, a clear differential between binary and ternary QDs was required to be established which clearly revealed the relevance of surface chemistry on the QD–lysozyme interaction.

Elementary Education in India in the Era of Universalization of Education: Instrument of Access or the Perpetuation of Inequality

Abstract Sixty years of policymaking in the arena of elementary educational reforms in India and global focus through the Millennium Development Goals (MDGs) have seen progress along with persisting inequality in access to education especially for socioeconomic and marginalized sections across the regions. This article focuses on analysis of two goals of MDGs which is related to universalization of education and reducing gender inequality in access to elementary education after introduction of policy interventions such as Sarva Shiksha Abhiyan (SSA) and Right to Education (RTE) Act in India through Gender Equity Index (GEI) and Disparity Index (DI) in Gross Enrollment Ratio (GER). Results are still consistent with the fact that even after incentives such as SSA and RTE, the scenario of elementary education has not changed much for the deprived sections, even it has shown a declining trend after 2009 for Scheduled Tribes (ST) children. The social reproduction of inequality is being manifested now in the quality of elementary education in India.