Manmana Yanawut, Macka Mirek, Nuchtavorn Nantana
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mahidol University 447 Sri-Ayudhaya Rd., Rajathevee Bangkok 10400 Thailand
School of Natural Sciences and Australian Centre for Research on Separation Science (ACROSS), University of Tasmania Private Bag 75 Hobart 7001 Australia.
RSC Adv. 2024 Nov 11;14(49):36142-36151. doi: 10.1039/d4ra05358c.
Distance-based detection (DbD) on paper-based microfluidic analytical devices (μPADs) has emerged as a promising, cost-effective, simple, and instrumentation-free assay method. Broadening the applicability of a new way of immobilization of reagent for DbD on μPADs (DμPADs) is presented, employing an ion exchange (IE) interaction of an anionic metallochromic reagent, 2-(5-bromo-2-pyridylazo)-5-[-propyl--(3-sulfopropyl)amino]phenol (5-Br-PAPS), on the anion-exchange filter paper. The IE DμPADs demonstrate superiority over standard cellulose filter paper in terms of the degree of reagent immobilization, detection sensitivity, and clear detection endpoints due to the strong retention of 5-Br-PAPS. The study investigated various parameters influencing DbD, including 5-Br-PAPS concentrations (0.25-1 mM), buffer types (acetic acid-Tris, MES), buffer concentrations (20-500 mM), and auxiliary complexing agents (acetic, formic, and glycolic acids). Subsequently, the performance of 17 metals (Ag, Cd, Co, Cr, Cu, Fe, Hg, La, Mn, Ni, Pb, Ti, Zn, Al, As, Fe, and V) was evaluated, with color formation observed for 12 metals. Additionally, the paper surface was examined using SEM and SEM-EDX to verify the suitability of certain areas in the detection channel for reagent immobilization and metal binding. This method demonstrates quantitation limits of metals in the low μg mL range, showing great potential for the rapid screening of toxic metals commonly found in herbal supplements and cosmetics regulated by the Food and Drug Administration (FDA). Thus, it holds promise for enhancing safety and regulatory compliance in product quality assessment. Furthermore, this method offers a cost-effective, environmentally sustainable, and user-friendly approach for the rapid visual quantification of heavy metals for in-field analysis, eliminating the need for complex instrumentation.
基于距离的检测（DbD）在纸基微流控分析装置（μPADs）上已成为一种有前景的、经济高效、简单且无需仪器的检测方法。本文介绍了一种拓宽用于μPADs（DμPADs）上DbD试剂固定新方法适用性的方法，该方法利用阴离子金属显色试剂2-(5-溴-2-吡啶偶氮)-5-[-丙基--(3-磺丙基)氨基]苯酚（5-Br-PAPS）在阴离子交换滤纸上的离子交换（IE）相互作用。由于5-Br-PAPS的强保留性，IE DμPADs在试剂固定程度、检测灵敏度和清晰的检测终点方面优于标准纤维素滤纸。该研究调查了影响DbD的各种参数，包括5-Br-PAPS浓度（0.25 - 1 mM）、缓冲液类型（乙酸 - Tris、MES）、缓冲液浓度（20 - 500 mM）和辅助络合剂（乙酸、甲酸和乙醇酸）。随后，评估了17种金属（Ag、Cd、Co、Cr、Cu、Fe、Hg、La、Mn、Ni、Pb、Ti、Zn、Al、As、Fe和V）的性能，观察到12种金属形成了颜色。此外，使用扫描电子显微镜（SEM）和扫描电子显微镜 - 能量色散X射线光谱仪（SEM-EDX）检查纸张表面，以验证检测通道中某些区域用于试剂固定和金属结合的适用性。该方法显示出低μg/mL范围内金属的定量限，对于快速筛查美国食品药品监督管理局（FDA）监管的草药补充剂和化妆品中常见的有毒金属具有巨大潜力。因此，它有望在产品质量评估中提高安全性和监管合规性。此外，该方法为现场分析中重金属的快速视觉定量提供了一种经济高效、环境可持续且用户友好的方法，无需复杂的仪器。
