A paper-based colorimetric microfluidic sensor fabricated by a novel spray painting prototyping process for iron analysis

Abstract

A novel, simple, and low-cost spray painting technique has been developed for the fabrication of microfluidic paper-based devices. The devices that we developed utilize aerosol spray paint to build hydrophobic barriers and employ a hole puncher to obtain paper-based patterned layers and paper dots without using any specialized instruments (e.g., without a laser cutter). The entire manufacturing process is extremely simple, inexpensive, and rapid, which means that it can be applied broadly. Furthermore, the application of the device to iron detection was demonstrated. A linear relationship between the colour value and the iron concentration was observed from 0 to 0.02 g/L. The developed microfluidic paper-based device for iron detection exhibited a low detection limit (0.00090 g/L), good selectivity, and acceptable recovery.

The air-gap PAD: a roll-to-roll-compatible fabrication method for paper microfluidics

“…The current method, however, is applicable not only to our two device designs, the paper titrator 12 and the 12-lane PAD, 11,15,17,19,21,81,85,88 but also to the many PADs reported by other groups that involve spot tests and/or straight channels. 6,8,36,44,52,55,64–66,74,89–95…”

“…Many of the laboratory-based methods developed since, such as silanization, 28 chemical vapor deposition, 29 and plasma treatment, 30,31 suffer from the same issues. Others, like hand cutting, 32,33 hand drawing, [34][35][36] hand folding, 37 plotting, [38][39][40] craft cutting, 41 3D printing, 42,43 stamping, [44][45][46][47][48][49] wax dipping, 50 spraying, 51,52 and screen printing, [53][54][55][56] boast low cost and require little equipment, but still suffer from low throughput and high hands-on labor. When wax printing was applied to μPAD fabrication, it was soon heralded as the method of choice for μPAD fabrication due to its reasonable cost, moderate throughput, simple operation, and ease of prototyping.…”

Sensitive Detection of BRCA1 Gene Based on Target Proximity Induced Quenching of the Fluorescence of Copper Nanoclusters

“…These results indicated that the fluorescent sensor based on CuNCs provided a reliable and practical platform for the detection of BRCA1 gene in real sample. More importantly, based on the work done by our group in the microfluidic colorimetric detection, [53][54][55][56] the fluorescent red emission of CuNCs in this work could be recorded as measured color values in the red, green, blue (RGB) color system. In further work, the fluorescent sensor would be transferred to a microfluidic chip for point-ofcare testing, offering high sample throughput, portability, low-cost detection and no requirement for the fluorescence spectrometer.…”

Semi-quantitative analysis of nickel: counting-based μPADs built via hand drawing and yellow oily double-sided adhesive tape

“…24 Although these work have made a huge contribution to the eld of PoP-based mPADs, the hydrophobic barrier is still constructed with wax in most of the methods, which cannot support solutions such as surfactants and organic solvents. 25 Therefore, our group have tried to use other substances to construct the hydrophobic boundaries of mPADs [26][27][28][29][30] and found that adhesive tape performed very good hydrophobicity. 28 Inspired by this, double-sided adhesive tape could be used as the main ingredient to manufacture the ink, paving a new way for the development of the PoP fabrication strategy.…”