3D-printing and MATLAB assisted ratiometric-sensing platform for visual on-site sensing of tetracycline using color conversion strategy

In this research, a ratiometric-sensing platform (ZIF-8/CDs) that combines non-fluorescence metal–organic frameworks (ZIF-8) with blue-green fluorescent carbon dots (CDs) has been developed for the determination of tetracycline (TC) with high sensitivity and selectivity in real samples. For this purpose, ZIF-8 with polyhedral structure was synthesized, which could form aggregation-induced emission (AIE) effect through electrostatic, hydrogen bonding, π-π stacking, and coordination interactions in the presence of TC, leading to enhanced intensity with a bright yellow fluorescence at 516 nm, acting as a response signal. However, the fluorescence intensity of blue-green fluorescent CDs maintained practically constant at 466 nm, serving as a reference signal. Furthermore, we integrate MATLAB algorithm and 3D-printing technology with the ZIF-8/CDs complex into a ratiometric-sensing platform for semi-quantitative detection of TC, in which 3D-printing technology is responsible for engineering an integrated dark chamber to achieve the fluorescence images of real samples, whereas MATLAB with the image processing functions and data processing capabilities utilizes to develop a mini program for calculating the RGB values of the obtained images. Consequently, the ratiometric-sensing platform in a simple, rapid, and economic way without any complicated process and expensive instruments could be used for visual/onsite detection of TC in real samples.