Easy as 1,2,3: Click chemistry is used for the synthesis of 1,2,3-triazole wherein the Cu^I is used as catalyst to obtain 1,4-disubstituted triazole as the sole product (see scheme). This review explains the excellent use of click chemistry for the synthesis of a number of biologically important intermediates, linkers, lead molecules, and various drugs.

All in red: This Focus Review concentrates on the emerging class of near-infrared (NIR) organic compounds containing the three types of chromophores, conjugated polyene, polymethine, and donor–acceptor, whose absorption and emission wavelengths are typically above 800 nm. The NIR-absorbing, -fluorescence, and -photosensitizing properties have been explored for applications in heat absorbers, solar cells, and NIR light-emitting diodes.

CS the day: Organosulfur compounds, including a wide range of natural products and drugs, have received considerable attention over the past few decades, owing to their remarkably bioactivity in biochemistry and medicinal chemistry. Numerous excellent sulfuration agents have been developed for the construction of CS bonds. In this review, the various strategies for CS bond formation are collected according to their sulfuration agents.

Cys-tematic modification: Cysteine is a versatile amino acid for selective chemical modification of proteins. Both chemical and biological innovations made possible by cysteine modification are highlighted in this Focus Review.

Count on the dots! Graphene oxide (GO; see figure) and graphene quantum dots (GQDs) have many attractive features; they are low-cost, non-toxic, photo-stable, water-soluble, biocompatible, and environmentally friendly. Most importantly, they may act as either fluorophores or quenchers in fluorescent bio- and chemosensors. The origin and mechanisms of this behavior and their applications as sensors in a broad range of areas of interest is discussed.