Ratiometric upconversion luminescence sensing platform for visual monitoring of antiarrhythmic drug level in serum

Arrhythmia seriously threatens life and health, it requires long-term use of antiarrhythmic drugs such as mexiletine and needs to monitor the dosage of drugs in the body to ensure efficacy and avoid serious side effects. Here, we designed a sensing platform for real-time visual monitoring of drug efficacy using a ratiometric upconversion probe, which overcomes the fluorescence background interference in the serum, and improves the resolution and accuracy of visual detection. By combining lanthanide-doped upconversion nanoparticles (UCNPs) with readily available organic dyes, an efficient upconversion nanoprobe was constructed under the reaction mechanism of internal filtration effect (IFE) to realize the quantitative detection of mexiletine in serum. Due to the addition of mexiletine, the characteristic emission peak of the probe at 540 nm changes, while the fluorescence intensity at 655 nm is unchanged. Therefore, the visual detection of mexiletine in serum is realized according to the fluorescence intensity changes of I 540 /I 655 . In addition, the designed sensing platform is combined with a smartphone to realize real-time visualization and quantitative monitoring of mexiletine, and the detection limits in fluorescence and colorimetric modes are as low as 55.6 nM and 469.75 nM respectively, consequently resulting in sensitive monitoring the effective dosage of drugs in the serum. The proposed detection platform provides a new sensing strategy for the visual determination of antiarrhythmic drugs and an instant device to warn the treatment process of the disease immediately.