Amidothiourea linked acridinedione derivatives selectively detect Hg²⁺ in unbuffered aqueous solution under broad pH range with both single- and two-photon excitation. The observed linear fluorescence intensity change allows the quantitative detection of Hg²⁺ in the concentration range of 22 nM–0.33 μM with the lower detection limit of 2 nM.

ZnO nanorods were capped with a simple amino acid, viz., L-alanine to increase the carrier concentration and improve the performance of ZnO/CuI heterojunction diodes. The effect of L-alanine capping on the morphology, structural, optical, electrochemical and electrical properties of ZnO nanorods had been studied in detail. The stable structure with two equally strong Zn–O coordinate bonds predicted by density functional theory was in agreement with the experimental results of FTIR spectroscopy. Due to the presence of electron-releasing (+I effect) moieties in L-Alanine, the carrier concentration of capped ZnO nanorods was two orders of magnitude higher and the ZnO/CuI heterojunction device showed more than a two-fold increase in the photovoltaic power conversion efficiency.