Electrochemistry and Optical Spectroscopy Center of Excellence (EOSCE), Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.
The Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, Patumwan, Bangkok, 10330, Thailand.
Mikrochim Acta. 2021 Mar 26;188(4):140. doi: 10.1007/s00604-021-04793-2.
A microcapillary grooved paper-based analytical device capable of dual-mode sensing (colorimetric and electrochemical detection) was demonstrated for analysis of viscous samples (e.g., human saliva). Herein, a hollow capillary channel was constructed via laser engraved micropatterning functions as a micropump to facilitate viscous fluidic transport, which would otherwise impede analysis on paper devices. Using salivary thiocyanate as a model analyte, the proposed device was found to exhibit a promising sensing ability on paper devices without the need for sample pretreatment or bulky instrumentation, as normally required in conventional methods used for saliva analysis. An extensive linear dynamic range covering detection of salivary thiocyanate for both high and trace level regimes (5 orders of magnitude working range) was collectively achieved using the dual-sensing modes. Under optimal conditions, the limit of detection was 6 μmol L with a RSD of less than 5%. An excellent stability for the μpumpPAD was also observed for over 30 days. Real sample analysis using the proposed device was found to be in line with the standard chromatographic method. Benefitting from simple fabrication and operation, portability, disposability, low sample volume (20 μL), and low cost (< 1 USD), the μpumpPAD is an exceptional alternative tool for the detection of various biomarkers in saliva specimens.
一种能够进行双模感应（比色和电化学检测）的微毛细管刻痕纸基分析装置，可用于分析粘性样品（例如人唾液）。在此，通过激光刻蚀微图案构建了一个中空的毛细管通道，该通道具有微泵的功能，可促进粘性流体的输送，否则这会阻碍纸基装置上的分析。使用唾液中的硫氰酸盐作为模型分析物，发现该装置在无需样品预处理或传统用于唾液分析的大型仪器的情况下，在纸基装置上具有良好的感应能力。使用双感应模式，可实现涵盖高浓度和痕量水平范围（5 个数量级工作范围）的唾液硫氰酸盐检测的广泛线性动态范围。在最佳条件下，检测限为 6 μmol·L，相对标准偏差（RSD）小于 5%。μpumpPAD 的稳定性也非常好，超过 30 天。使用所提出的装置进行实际样品分析与标准色谱法一致。得益于简单的制造和操作、便携性、一次性使用、低样品量（20 μL）和低成本（<1 美元），μpumpPAD 是用于检测唾液样本中各种生物标志物的一种出色的替代工具。
