Del Sole Roberta, Stomeo Tiziana, Mergola Lucia
Department of Engineering for Innovation, University of Salento, Via per Monteroni Km 1, 73100 Lecce, Italy.
Center for Bio-Molecular Nanotechnology, Istituto Italiano di Tecnologia, Via Barsanti 14, 73010 Arnesano, Italy.
Polymers (Basel). 2023 Dec 19;16(1):3. doi: 10.3390/polym16010003.
l-Kynurenine (l-Kyn) is an endogenous metabolite produced in the catabolic route of l-Tryptophan (l-Trp), and it is a potential biomarker of several immunological disorders. Thus, the development of a fast and cheap technology for the specific detection of l-Kyn in biological fluids is of great relevance, especially considering its recent correlation with SARS-CoV-2 disease progression. Herein, a disposable screen-printed electrode based on a molecularly imprinted polymer (MIP) has been constructed: the -Phenylenediamine monomer, in the presence of l-Kyn as a template with a molar ratio of monomer/template of 1/4, has been electropolymerized on the surface of a screen-printed carbon electrode (SPCE). The optimized kyn-MIP-SPCE has been characterized via cyclic voltammetry (CV), using [Fe(CN))] as a redox probe and a scanning electron microscopy (SEM) technique. After the optimization of various experimental parameters, such as the number of CV electropolymerization cycles, urine pretreatment, electrochemical measurement method and incubation period, l-Kyn has been detected in standard solutions via square wave voltammetry (SWV) with a linear range between 10 and 100 μM (R = 0.9924). The MIP-SPCE device allowed l-Kyn detection in human urine in a linear range of 10-1000 μM (R = 0.9902) with LOD and LOQ values of 1.5 and 5 µM, respectively. Finally, a high selectivity factor α (5.1) was calculated for l-Kyn toward l-Trp. Moreover, the Imprinting Factor obtained for l-Kyn was about seventeen times higher than the IF calculated for l-Trp. The developed disposable sensing system demonstrated its potential application in the biomedical field.
L-犬尿氨酸（L-Kyn）是L-色氨酸（L-Trp）分解代谢途径中产生的一种内源性代谢物，它是多种免疫性疾病的潜在生物标志物。因此，开发一种快速、廉价的技术用于生物体液中L-Kyn的特异性检测具有重要意义，特别是考虑到其最近与SARS-CoV-2疾病进展的相关性。在此，构建了一种基于分子印迹聚合物（MIP）的一次性丝网印刷电极：在L-Kyn作为模板存在的情况下，以单体/模板摩尔比为1/4的对苯二胺单体在丝网印刷碳电极（SPCE）表面进行电聚合。通过循环伏安法（CV），使用[Fe(CN))]作为氧化还原探针和扫描电子显微镜（SEM）技术对优化后的kyn-MIP-SPCE进行了表征。在优化了各种实验参数，如CV电聚合循环次数、尿液预处理、电化学测量方法和孵育期后，通过方波伏安法（SWV）在标准溶液中检测到L-Kyn，线性范围为10至100 μM（R = 0.9924）。MIP-SPCE装置能够在人尿中检测L-Kyn，线性范围为10-1000 μM（R = 0.9902），检测限（LOD）和定量限（LOQ）分别为1.5和5 μM。最后，计算出L-Kyn对L-Trp的高选择性因子α（5.1）。此外，L-Kyn获得的印迹因子比L-Trp计算得到的印迹因子高约17倍。所开发的一次性传感系统展示了其在生物医学领域的潜在应用。
