Highly Selective and Instant Ratio Fluorescence-Scattering Sensor for Phosphate Detection in a Water Environment by a Stable Eu3+/Y3+-Modified Nitrogen-Doped Carbon Quantum Dot

shows a high sensitivity, a low detection limit of 0.08 μM, a rapid response time of within 2 s, and a wide detection range from 1 to 150 μM. Moreover, the proposed probe showed excellent selectivity and stability, and the relative standard deviation (RSD) of seven cycles of Pi detection is only 0.559%. Furthermore, the accurate detection of Pi (RSD < 5%) in real environmental water samples confirmed the practicality of the proposed sensor. This ratio fluorescence-scattering sensor provides a novel method for the detection of Pi with a simple preparation process and excellent detection performance, having great application potential for the fast on-site detection of Pi.