Establishment of a R-Sphere labelled immunoassay platform and its rapid combined quantitative detection of ketamine and morphine in serum.

Background And Aims: Ketamine and morphine are among the most commonly abused drugs. Ketamine is classified as a new psychoactive substance, while morphine represents the opioid class. These two substances may exhibit synergistic or antagonistic effects in their pharmacological actions, and their combined abuse could lead to more severe health risks, such as respiratory depression. Therefore, simultaneous detection is crucial for comprehensive monitoring of drug abuse. This study developed a test strip capable of detecting both ketamine (KET) and morphine (MOP) in serum, utilizing Raman spectroscopy technology to meet the needs of various application scenarios.

Methods: A mixture of Raman microsphere-labelled KET and MOP antibodies was mixed with a mixed standard solution of KET and MOP and added dropwise to the sample pad of the prepared KET and MOP co-assay test strip, chromatographed for 10 min, and then the Raman spectra and Raman signals at the T-line were detected using a Raman spectrometer.

Results: The KET and MOP showed good correlation with the Raman signal response values in the concentration ranges of 0.0-100.0 ng/mL and 0.0-4.0 ng/mL, and the limits of detection (LODs) were 1.1986 ng/mL and 0.0113 ng/mL with the coefficients of variation (CV) of less than 10 %, the recoveries were in the ranges of 90 %-110 %, and interfering substances had no effect on the detection results.

Conclusion: In this study, we developed a method for the quantitative detection of KET and MOP based on the spectroscopic properties of Raman microsphere (R-Sphere) and the principle of competitive immunity, which has the advantages of simple operation, rapidity, high sensitivity, and the possibility of combined detection, which makes the detection efficiency greatly improved.