Near infrared-response ratiometric fluorescence sensor for the sensitive detection of Cu2+

The design of novel Cu 2+ quantitative sensors with highly sensitivity and selectivity is a hot topic of modern chemistry . Herein, a novel ratiometric fluorescence (PL) sensor based on the red-emitting CdTeS quantum dots (QDs) and blue-emitting polyethyleneimine-functionalized carbon dots (PEI-CDs) was firstly designed for sensing Cu 2+ . In the presence of Cu 2+ , a good linear relationship between the ratios (F 520 /F 690 ) of the two peak intensities and the concentrations of Cu 2+ was observed in the range of 0.01–250 µM with the correlation coefficient (R 2 ) of 0.993 and the detection limit as low as 8.07 nM. The ratiometric nanosensor was also used to successfully determine Cu 2+ in plasma samples with satisfactory results obtained. Therefore, we hold the opinion that the developed ratiometric fluorescent sensor based on CdTeS QDs/PEI-CDs will provide technical support for the point-of-caretesting of Cu 2+ .