Affordable and Sustainable Sample Preparation (AS₂P) Research Group, Analytical Chemistry Departament, Instituto Químico para la Energía y el Medioambiente (IQUEMA), Universidad de Córdoba, Campus de Rabanales, Marie Curie building, E-14071, Córdoba, Spain.
Mikrochim Acta. 2024 Nov 4;191(12):722. doi: 10.1007/s00604-024-06787-2.
An electroanalytical method based on disposable screen-printed carbon electrodes modified with non-toxic carbonaceous nanodots is proposed as a reliable and effective device for codeine determination in biological fluids and soft drinks. Graphene quantum dots (GQDs), carbon quantum dots (CQDs) and carbon nanodots (CNDs) were evaluated as electrode modifiers for the determination of the drug. The electroactive areas of the modified electrodes were assessed by cyclic voltammetry using potassium ferricyanide. Results demonstrated that GQDs provided the best analytical response for codeine, displaying an intense and well-defined anodic wave approximately 0.9 V vs reference electrode. The method exhibits an acceptable linear dynamic range, low limits of detection and quantification (0.21 and 0.73 µM, respectively), and satisfactory precision (below 3.9% expressed as relative standard deviation (RSD)) in saliva. Only the analysis of biofluids requires a simple extraction protocol. The feasibility and applicability of this novel approach were assessed by determining codeine in different matrices, with recoveries ranging from 69 to 112%. This cost-effective, simple, easily miniaturised and portable method was applied not only to biofluids but also for the direct detection of codeine in soft drinks combined with a codeine-enriched syrup, a medication that is being used to adulterate beverages, particularly at specific events (drinking and nightclub parties). There is no need for any sample treatment, demonstrating its versatility in analysing beverages for potential adulteration as well.
提出了一种基于一次性丝网印刷碳电极修饰无毒碳纳米点的电化学分析方法，作为一种可靠有效的生物体液和软饮料中可待因测定装置。评估了石墨烯量子点 (GQDs)、碳量子点 (CQDs) 和碳纳米点 (CNDs) 作为修饰电极测定药物的性能。通过使用铁氰化钾的循环伏安法评估了修饰电极的电活性面积。结果表明，GQDs 为可待因提供了最佳的分析响应，在参考电极约 0.9 V 处显示出强烈而清晰的阳极波。该方法在唾液中具有可接受的线性动态范围、低检测限和定量限（分别为 0.21 和 0.73 µM）和令人满意的精密度（低于 3.9%，表示为相对标准偏差 (RSD))。仅生物流体的分析需要一个简单的提取方案。通过在不同基质中测定可待因来评估这种新方法的可行性和适用性，回收率范围为 69%至 112%。这种具有成本效益、简单、易于小型化和便携的方法不仅应用于生物流体，还可直接检测软饮料中的可待因，结合富含可待因的糖浆，这种药物被用于掺假饮料，特别是在特定活动（饮酒和夜总会聚会）中。不需要任何样品处理，证明了其在分析潜在掺假饮料方面的多功能性。
