Novel turn-on fluorescent biosensors for selective detection of cellular Fe3+ in lysosomes: Thiophene as a selectivity-tuning handle for Fe3+ sensors

Iron-selective turn-on sensors are indispensable tools for understanding iron-related cell death processes and human diseases. In this study, we report a novel class of fluorescent sensors derived from an indolizino[3,2-c]quinoline scaffold that exhibit high selectivity for Fe3+ over other biologically abundant cations in cells, including Fe2+, Al3+, Zn2+, and Mn2+. IQ18 works as a ratiometric sensor with a Kd value of 7.1 × 10 −7 M and a...