Low cost, disposable paper based electrical sensor to examine the analyte concentration in an extremely small volume of sample solution is essential for environmental and healthcare applications. For the development of paper based devices, sophisticated instruments are essential to pattern electrode on the top surface of the paper. In most cases, such fabricated device results in direct contact with the analyte solution on the surface of the electrode during electrical detection and leads to high electrical double layer capacitance. In this work, we have focused to reduce the double layer capacitance by fabricating hand drawn electrode paper sensor utilising the reverse side of the paper. This design acts as a sample storage and facilitate impedimetric sensing of ionic concentration of analyte solution using a few microlitre. Droplet formation at the bottom of the paper in the confined area is visually monitored to reduce sample wastage. The interaction between two different electrode materials (graphite and silver) on the paper substrate with the different volume and concentration of the electrolyte is analysed to improve the robustness and sensitivity of the measurement. Simultaneously, we observed a reduction in the electrical double layer effect on the low sample volumes. The proposed paper based sensor shows the enhanced impedance stability on silver electrode patterned paper chip than graphite electrode paper chip to detect the different ionic concentration of artificial sweat sample. Finally, it demonstrates that paper chip has great potential as a disposable diagnostics sensor in healthcare applications.

用于检测极少量样品溶液中分析物浓度的低成本、一次性纸基电子传感器对于环境和医疗保健应用至关重要。对于基于纸的设备的开发，复杂的仪器对于在纸的顶面上形成电极图案是必不可少的。在大多数情况下，这种制造的装置会导致在电检测期间与电极表面上的分析物溶液直接接触，并导致高双电层电容。在这项工作中，我们专注于通过利用纸的背面制造手绘电极纸传感器来降低双电层电容。这种设计充当样品储存器，并有助于使用几微升对分析物溶液的离子浓度进行阻抗检测。在受限区域内的纸底部形成的液滴通过目视监测以减少样品浪费。分析具有不同电解液体积和浓度的纸基材上两种不同电极材料（石墨和银）之间的相互作用，以提高测量的稳健性和灵敏度。同时，我们观察到双电层效应对低样品体积的降低。所提出的纸基传感器表明，与石墨电极纸芯片相比，银电极图案纸芯片具有更高的阻抗稳定性，可检测人造汗液样品的不同离子浓度。最后，它表明纸芯片在医疗保健应用中作为一次性诊断传感器具有巨大的潜力。