Fluorescent/Colorimetric Dual-Mode Biosensor for Ultrasensitive Detection of Cadmium by the Combination of PER and CdTe QDs

Through target-mediated primer exchange reaction (PER) cascade amplification of DNAzyme cleavage Ag⁺-HP, combined with CdTe quantum dots (CdTe QDs) for detecting trace targets in the environment, a sensitive and efficient unlabeled visualization and fluorescence dual-mode biosensor strategy for rapid Cd²⁺ detection was established. It can make the detection limit as low as 214.17 pM. This strategy utilizes target-mediated PER cascade amplification DNAzyme to complete signal amplification, providing a specific signal amplification process to enable the biosensor to have high accuracy and strong sensitivity. Furthermore, the coupling of CdTe QDs completes the signal presentation and improves the stability of the signal conversion. Meanwhile, by integrating intelligent software to deepen the application of the colorimetric method in the rapid initial detection of actual samples, it provides a basis for judging whether further detection is needed. This strategy has established a platform for the detection of pollutants in the environment and shows great potential in the detection of environmental samples.