Quantitative detection of morphine based on an up-conversion luminescent system.

An up-conversion luminescent material converts low-frequency excitation light into high-frequency emission light through photons and has the advantages of long fluorescence lifetime, narrow emission peak and low toxicity; thus, this material has many unique applications in the detection and identification of biomolecules. In this study, an ultrasensitive up-conversion luminescent system for the quantitative detection of morphine was developed. The principle of this system is based on infrared light as an excitation light source to convert light with lower energy into excitation light with higher energy. The up-conversion luminescent material is used as a label and through the processing and analysis of the excitation light intensity, the quantitative detection of morphine concentration is achieved. At the same time, the excitation light can avoid the interference and scattering phenomenon of the autofluorescence of the biological sample, which improves the system's detection sensitivity. An algorithm for light intensity processing is added to process image data, reduce the interference caused by noise during image acquisition and improve the accuracy of morphine detection. The T/C value is calculated to achieve the quantitative detection of morphine with a detection limit of 0.1 ng mg-1 and detection time within 0.5 min. The up-conversion luminescent system has the advantages of quantitative detection, convenience, portability, short detection time and low price. Thus, the system can be used for the detection of other biomolecules or for other applications such as food analysis, environmental detection, national security, etc.