Punnoy Pornchanok, Aryal Prakash, Hefner Claire E, Brack Eric, Rodthongkum Nadnudda, Potiyaraj Pranut, Henry Charles S
Department of Materials Science, Faculty of Science, Chulalongkorn University, Soi Chula12, Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
Department of Chemistry, Colorado State University, Fort Collins, CO, 80523, United States.
Anal Chim Acta. 2025 Jun 22;1356:344031. doi: 10.1016/j.aca.2025.344031. Epub 2025 Apr 10.
Heavy metal and nutrient contamination are growing global issues necessitating monitoring water resources. While laboratory-based platforms for detecting these contaminants are sensitive and accurate, they require centralized facilities, trained personnel, and significant costs. Microfluidic paper-based analytical devices have emerged as a low-cost alternative for on-site detection of these water contaminants; however, these platforms struggle with slow assay times, loss of analyte, and the need for precise volumetric pipetting. Moreover, these platforms often focus on detecting only one subgroup of contaminants, limiting the potential for comprehensive measurements.
We developed a capillary flow-driven, single-dip dual-sided detection system, enabling rapid, multiplex detection of heavy metals and nutrients in a single user step. The sensor enables both qualitative visual analysis and quantitative analysis via a smartphone app for real-time and on-site detection of Ni, Fe, Cu, NO and PO. The limits of detection (LoD) and quantification (LoQ) were calculated as 1.3 and 4.4 ppm for Ni, 0.3 and 0.9 ppm for Fe, 0.2 and 0.6 ppm for Cu, 0.4 and 1.2 ppm for NO, and 0.5 and 1.6 ppm for PO. Selectivity was achieved through masking strategies in each detection zone. The sensors were stable for >4 weeks under ambient conditions. Spike-recovery analysis was performed using river, tap, pond, and commercial drinking water, achieving recoveries between 86 and 112 % with accuracy and precision below 15 % RSD for all samples.
This multiplex sensor offers a solution to overcome the current limitations of paper-based devices, allowing for a more comprehensive analysis of multiple contaminant classes.
重金属和营养物质污染是日益严重的全球性问题，需要对水资源进行监测。虽然基于实验室的检测这些污染物的平台灵敏且准确，但它们需要集中的设施、经过培训的人员以及高昂的成本。基于微流控纸的分析设备已成为现场检测这些水中污染物的低成本替代方案；然而，这些平台存在检测时间长、分析物损失以及需要精确体积移液的问题。此外，这些平台通常仅专注于检测一类污染物中的一个亚组，限制了进行全面测量的可能性。
我们开发了一种毛细管流动驱动的单浸双面检测系统，能够在单个用户操作步骤中快速、多重检测重金属和营养物质。该传感器通过智能手机应用程序实现定性视觉分析和定量分析，用于实时现场检测镍、铁、铜、硝酸根和磷酸根。镍的检测限（LoD）和定量限（LoQ）分别计算为1.3 ppm和4.4 ppm，铁为0.3 ppm和0.9 ppm，铜为0.2 ppm和0.6 ppm，硝酸根为0.4 ppm和1.2 ppm，磷酸根为0.5 ppm和1.6 ppm。通过在每个检测区域采用掩蔽策略实现了选择性。传感器在环境条件下稳定超过4周。使用河水、自来水、池塘水和市售饮用水进行加标回收分析，所有样品的回收率在86%至112%之间，准确度和精密度低于15%相对标准偏差（RSD）。
这种多重传感器提供了一种解决方案，以克服当前基于纸的设备的局限性，从而能够对多种污染物类别进行更全面的分析。
