Optically responsive switchable ionic liquid for internally-referenced fluorescence monitoring and visual determination of carbon dioxide.

Modulation in the local viscosity and polarity within a reversible carbamate ionic liquid system forms the basis for the fluorescence excimer-based estimation of CO(2). Inherently self-referencing, the photonic response to CO(2) recognition shows excellent sensitivity and complete reversibility, making possible a striking visual display discernible to the naked eye.