Fabrication of microfluidic paper-based channels by inkjet printing process for analytical applications

Microfluidic paper-based channels play an important role in microfluidic paper-based analytical devices (μPADs). There are some fabrication methods which could be utilised to fabricate microfluidic channels on paper substrate. Among these methods, inkjet printing process is considered as a promising fabrication method with many advantages such as low-cost, material saving, high precision, etc. The aim of this work is to apply inkjet printing technology to fabricate paper channels of μPADs. A new design of μPAD was proposed in this paper to demonstrate how to fabricate inkjet-printed hydrophobic lines to make paper-based biosensor. Biological target of our μPADs is human chOrionic gonadotropin (hCG). Colorimetric signals from μPADs were captured by digital camera and measured by ImageJ software, which showed that these μPADs can determine hCG in the range from 1,000 to 10,000 ng ml−1. These results showed that piezoelectric inkjet printing technology can fabricate 250 μm-width hydrophobic lines on paper substrate, helping in fabricating μPADs in next applications.