Copper ion ratio chemiluminescence probe based on chemiluminescence resonance energy transfer

We synthesized the water-soluble CdTe quantum dots (CdTe QDs) with longer emission wavelength, constructed the luminol-CdTe QDs chemiluminescence resonance energy transfer (CRET) system, and realized the high selectivity ratio detection for Cu2+. Herein, based on the Irving-William sequence, it was found that the para-magnetic ion Cu2+ generally binds more strongly than the diamagnetic ion Cd2+. When Cu2+ is added to the system, Cu2+ tends to bind to the sulfhydryl group (S-H) of stabilizer on CdTe QDs, leading to surface defects of CdTe QDs, which quenches the chemiluminescence (CL) signal remarkably. Meanwhile, due to the superior coordination ability of Cu2+ and ratio detection, the system has better selectivity and anti-interference perfor-mance. The method achieved a highly sensitive, selective, yet reliable measurement of Cu2+ in the concentration range of 0.5 x 10-7-20 x 10-7 M, with a low detection limit of 8.4 nM. Importantly, the sensor has been suc-cessfully exploited to detect Cu2+ in tap water and lake water.

Automated summary

We synthesized water-soluble CdTe quantum dots (CdTe QDs) with longer emission wavelength and constructed a luminol-CdTe QDs chemiluminescence resonance energy transfer (CRET) system for high selectivity ratio detection of Cu2+. The system discovered that the paramagnetic ion Cu2+ generally binds more strongly to the sulfhydryl group (S-H) on CdTe QDs, which leads to surface defects and quenches the chemiluminescence (CL) signal. The method achieved a highly sensitive, selective, and reliable measurement of Cu2+ with a low detection limit of 8.4 nM, and has successfully detected Cu2+ in tap water and lake water.