Multi-color Fluorescence Sensing Analysis Based On Telluride Quantum Dots And Its Bacterial Inhibition Performance

A class of luminous materials known as semiconductor quantum dots（QDs）has received a lot of attention recently.Their unique structure gives them properties such as dielectric confinement effect,quantum size effect,surface effect,and thus they derive unique luminescent properties.These properties make them play an increasingly important role in biochemistry,materials science,and analytical chemistry.In this paper,two multi-color optical sensing systems based on telluride QDs were constructed:（1）A triple-emission multi-color sensing platform based on Cd Te QDs for the monitoring of Cu²⁺and thiram;（2）A triple-emission multi-color sensing platform based on Cd Zn Te QDs for the monitoring of Hg²⁺and sulfide,and the inhibition performance of the two telluride QDs were investigated.The details of each system are as follows:1.The design of a deep learning-assisted smartphone integrated multi-color fluorescent probe optics for visual monitoring of Cu²⁺and thiram.The system consists of blue fluorescent carbon quantum dots（B-QDs）,green and red fluorescent Cd Te QDs（G-QDs and R-QDs）.When Cu²⁺is present,the fluorescence of G-QDs and R-QDs is simultaneously burst,while the fluorescence of B-QDs remains unchanged and the fluorescence color of the whole system changes from orange-red to blue.The addition of thiram restored the fluorescence intensity of G-QDs and R-QDs,while the fluorescence intensity of B-QDs was burst,and the system’s overall fluorescence altered from blue to red.In addition,with an increase in thiram concentration,the system’s UV absorption intensity changed.Experiments and density functional theory（DFT）verification show that the response of the sensing system to Cu²⁺and thiram is based on electron transfer effect,electrostatic adsorption and internal filtration effect（IFE）respectively.YOLO v3 algorithm-assisted smartphone integrated portable optical device achieved sensitive monitoring of Cu²⁺and thiram in the field.This sensing system has great potential for monitoring Cu²⁺content and thiram residues.2.The design of a deep learning-assisted smartphone integrated multi-color fluorescent probe optics for Hg²⁺and S^2-detection in water and lobster,and realize the visual monitoring of egg food freshness.The system consists of blue fluorescent carbon quantum dots（BU-CDs）,green and red fluorescent Cd Zn Te QDs（GN-QDs and RD-QDs）.GN-QDs and RD-QDs are burst by Hg²⁺and sulfide based on dynamic and static bursting principle,but the fluorescence of BU-CDs remains unchanged,so the system fluorescence shows multicolor changes.The experiments and DFT demonstrated that the doping of Zn enhanced the stability,quantum yield,and inhibition performance of the QDs.The combination of probes and hydrogels to prepare visual sensing labels enabled the monitoring of egg food freshness.Finally,a multi-algorithm-assisted smartphone device was used to achieve handheld monitoring of Hg²⁺and S^2-.The probe system has unlimited potential for assessing Hg²⁺and sulfide content,while the excellent antibacterial properties increase its certain possibility as an antimicrobial packaging material.