An Nd3+-sensitized Upconversion Fluorescence Sensor Coupled with Microwell Device for the Ratiometric Detection of Doxorubicin

In this work, we report an upconversion fluorescence sensor coupled with microwell device for the ratiometric detection of doxorubicin (DOX). The fabricated microwell device serve to greatly reduce the consumption of samples in the detection. The upconversion fluorescence sensor produces two-emission peaks located at 539 and 654 nm under the excitation of the 808 nm laser. In the presence of DOX, the fluorescence emission of upconversion nanoparticles at 539 nm can be effectively quenched via a fluorescence resonance energy transfer process while that of 654 nm remains unchanged. The fluorescence intensity ratio (F654/F539) shows a linear relationship with the concentration of doxorubicin in the range of 0-100 μM with a detection limit of 2 μM. The proposed detection strategy is simple, fast, accurate, and consumes less samples.