Colloidal gold immunochromatographic strips for the detection of kynurenine in clinical samples

Kynurenine (KYN), a metabolite of tryptophan, is currently receiving increasing attention as one of the biomarkers for clinical disease monitoring. To realize the determination of KYN in human plasma samples in the clinic, a specific monoclonal antibody (mAb) against KYN was prepared based on the structural characteristics of KYN. By optimizing the detection conditions, we obtained anti-KYN mAb 1G10 with a sensitivity of 143.66 ng/mL, and established a colloidal gold immunochromatographic assay (CGCA) platform for the qualitative and quantitative analysis of KYN in human plasma samples, using CGCA strips to meet the needs of clinical testing. The recoveries of the strips for the determination of KYN in plasma samples were in the range of 85.22%–99.72%, which were validated by liquid chromatography–tandem mass spectrometry (LC-MS/MS), and results were in good agreement with the LC-MS/MS method, indicating that the accuracy of the prepared CGCA strips was high. Based on the characteristics of low cost, high throughput and good specificity, the test strips will be widely applicable for clinical determination.