Single-Layered Paper-Based Microfluidic Devices Made by Paint-Spraying Technique with Great Barrier Resistance for Colorimetric Assays

Abstract

The single-layered paint-spraying paper based microfluidic devices (sp-μPADs) have been for the first time integrated with the colorimetric assay. The polymethyl methacrylate (PMMA) board was applied as the mask instead of the iron mask, reducing the power requirement of the cutting machine. The paint was sprayed into the paper, which blocked the pores of the paper and constructed the hydrophobic barrier on the paper. The paint barrier was highly resistant to the various kind of chemicals and the minimum channel dimensions was 1.4 mm. By using the PMMA masks with different designs, the sp-μPADs with different designs have been fabricated and successfully applied to the single analyte assay of iron or bovine serum albumin (BSA) and the simultaneous assay of copper and nickel. Moreover, the feasibility of the multiplexed assay of eight analytes was also demonstrated. The analytical performances indicated that the fabricated sp-μPADs offered a promising platform in the colorimetric assays of either single or multiple analytes.

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

“…50 mmol L −1 of DMG and 50 mmol L −1 of tris(hydroxy)aminomethane were dissolved in ethanol to prepare the assay reagent. 26 In this work, chitosan was used as an immobilization support, which has been successfully demonstrated by different authors in sensing studies on a microuidic scale. [31][32][33] 0.5% (m/v) chitosan was added into 2% (v/v) acetic acid solution and stirred for 30 minutes to prepare a chitosan solution.…”

“…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.…”

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.…”

Reducing Unspecific Protein Adsorption in Microfluidic Papers Using Fiber-Attached Polymer Hydrogels

“…Many of these fiber-specific characteristics have a direct influence on the fluid dynamics inside a paper channel and are, therefore, interesting candidates for fine-tuning the capillary flow [ 37 ]. Meanwhile, other groups largely focus on paper extrinsic manipulation of microfluidics [ 38 , 39 ].…”