Europium-based aminoclay containing carbon dots: A new visual fluorescence platform for visual point-of-care testing of tetracycline in various real samples

It is of vital significance to achieve accurate real-time detection of tetracycline (TC). In this research, the ratio fluorescence detection of tetracycline is realized by introducing europium-based aminoclay containing carbon dots with good sensitivity to tetracycline through subsequent surface modification. With the increase of tetracycline concentration, the fluorescence intensity of rare earth europium fluorophore increases continuously, while the fluorescence intensity of CDs is basically unchanged. The CIE chromaticity coordinate confirms that the luminous color of the probe can be adjusted continuously from blue to red. The results exhibit this approach owns the favourable linearity to TC within 0–12.5 μM and 10–25 μM, and the high sensitivity with a low detection limit of 3.133 nM. Moreover, it can entirely satisfy the requirements of field detection because the rapid monitoring time as short as 30 s. The multicolor fluorescence detection strategy is reliable and feasible in the field test of TC in various actual samples. In addition, a TC floating detector based on vertical float structure is designed to achieve the rapid visual detection of TC in simulated flow environment. The superiority of the sensing platform opens up a neo-pathway for point-of-care monitoring of TC residues.