基于CuInS2@ZnS量子点的ATP近红外荧光适配体传感器研究

Near-infrared Fluorescent Aptamer Sensor for ATP Based on CuInS2@ZnS Quantum Dots

摘要:

检测农作物体内腺苷三磷酸(ATP)水平对于评估作物生长代谢、监测环境胁迫反应、开展病理生理研究以及指导农业生产实践具有重要意义。为实现快速准确地检测和定量ATP，开发了一种基于CuInS2@ZnS量子点(QDs)的近红外荧光传感器。利用热分解法制备了CuInS2@ZnS QDs,通过MPA修饰赋予其负电荷,并与带正电荷的羧基壳聚糖形成CHIT/CuInS2@ZnS纳米复合材料。ATP的强负电荷适配体通过静电和氢键作用诱导纳米复合材料聚集，导致荧光猝灭。当目标物ATP与适配体特异性结合后，形成适配体-ATP复合物，从荧光探针表面解离，导致探针的荧光信号恢复。该传感器在5pmol/L至10nmol/L ATP浓度范围内,荧光强度(I/I0)与ATP浓度呈现良好的线性关系,检测限为1.67pmol/L。该传感器能够在复杂生物样品中有效区分和检测ATP,展现出优异的应用前景。

Abstract:

Detecting the level of adenosine triphosphate (ATP) in plants is of significant importance for evaluating plant growth and metabolism, monitoring plants’responses to environmental stresses, conducting research on plant pathology and physiological processes, as well as guiding agricultural production practices. A near-infrared fluorescent sensor for the sensitive detection of ATP was developed based on CuInS2@ZnS quantum dots (QDs). The CuInS2@ZnS QDs were prepared by using the hot decomposition method. Negatively charged MPA-modified CuInS2@ZnS QDs were able to interact with positively charged carboxymethyl chitosan, resulting in the formation of carboxymethyl chitosan-coated CHIT/CuInS2@ZnS nanocomposites. The aptamer of ATP, possessing a strong negative charge, induced aggregation of the positively charged nanocomposites through electrostatic and hydrogen bonding interactions, leading to fluorescence quenching. The sensor exhibited a linear relationship between the fluorescence intensity (I/I0) of the CHIT/CuInS2@ZnS nanocomposites and the logarithm of ATP concentration within the range of 5pmol/L to 10nmol/L. The detection limit of the sensor was determined to be 1.67 pmol/L. The research successfully established a CuInS2@ZnS quantum dot-based near-infrared fluorescent sensor for sensitively detecting ATP. This sensor has important theoretical significance and practical value for the growth and development of plants and the judgment of their stress responses to the external environment.