Nanoscale transport of merocyanine 540 within/near the plasmon field of gold nanoparticles was recognized as an effective inducer of single-excitation dual-emission ratiometric properties. With a high concentration of the signal transducer (ammonium), a 700% increase in fluorescence was observed at the new red-shifted emission maximum, compared to a nanoparticle free sensor membrane. A previously nonrecognized isosbestic point is demonstrated at 581.4 ± 0.1 nm. The mechanism can be utilized for enhanced and simplified ratiometric optical chemical sensors and potentially for thin film engineering to make solar cells more effective and stable by a broader and more regulated absorption.
![3(2H)-Benzoxazolepropanesulfonicacid,2-[4-(1,3-dibutyltetrahydro-4,6-dioxo-2-thioxo-5(2H)-pyrimidinylidene)-2-buten-1-ylidene]-,sodium salt (1:1) Structure](https://image.chemsrc.com/caspic/169/62796-23-0.png)