A rapid, inexpensive surface treatment for enhanced functionality of polydimethylsiloxane microfluidic channels

Abstract

A rapid, inexpensive method using alkoxysilanes has been developed to selectively coat the interior of polydimethylsiloxane (PDMS) microfluidic channels with an integral silicaceous layer. This method combines the rapid prototyping capabilities of PDMS with the desirable wetting and electroosmotic properties of glass. The procedure can be carried out on the open faces of PDMS blocks prior to enclosure of the channels, or by flowing the reagents through the preformed channels. Therefore, this methodology allows for high-throughput processing of entire microfluidic devices or selective modification of specific areas of a device. Modification of PDMS with tetraethoxysilane generated a stable surface layer, with enhanced wettability and a more stable electroosmotic flow rate than native PDMS. Modification of PDMS with 3-aminopropyltriethoxysilane generated a surface layer bearing amine functionalities allowing for further chemical derivatization of the PDMS surface.

Enhanced Triboelectric Performance of Modified PDMS Nanocomposite Multilayered Nanogenerators

“…These [PVA/GNP-PSS] 3 multilayers were prepared using an inexpensive and simple layer-by-layer (LbL) assembly process, which was advantageous for precise control of the thickness of the film [ 4 , 30 , 31 , 32 ]. Then, the modified PDMS negative TM layer and [PVA/GNP-PSS] 3 multilayer electrode were chemically linked by 3-aminopropylethoxysilane (APTES) as a coupling agent under mild reaction conditions without altering the desired properties of the composite films [ 33 , 34 ]. Finally, the GNP-PDMS nanocomposites, fabricated by adding 33 wt.% Na 2 CO 3 and 0.5 wt.% GNP and assembled with a [PVA/GNP-PSS] 3 electrode, achieved an open-circuit voltage and short-circuit current density of up to 270.2 V and 0.44 μA/cm 2 , respectively.…”

Laser-induced heating integrated with a microfluidic platform for real-time DNA replication and detection

“…Because of the specific properties of microchannels produced using polydimethyliloxane (PDMS), such as high light transmittance, ease of production, and chemical stability, PDMS has been extensively applied in the development of biomedical microsystems. [29][30][31][32][33][34][35][36][37] Although PDMS has many advantages, it is permeable to gases and organic molecules. 38 Many groups have investigated different forms of surface modification to prevent biosamples from being absorbed on the surface of PDMS during PCR; e.g., using compounds such as polyvinylpyrrolidone, 39 polybrene, 40 bovine serum albumin (BSA), 41 3-aminopropyltriethoxysilane, 28 and glycerol.…”

A fluorescence based method for the quantification of surface functional groups in closed micro- and nanofluidic channels

“…Silane coupling agents have gained widespread popularity as covalent linkers that can be used for the functionalization of silicon, glass, and polymers commonly used in microfluidics. [13][14][15][16][17] However, the reproducible deposition of high-quality silane layers inside microfluidic channels is often difficult, especially to researchers new to the field. 13 This is predominantly due to the combination of experimental challenges associated with flow-through systems and a simultaneous shortage of surface analysis methods able to provide validation and feedback in closed microfluidic a) Author to whom correspondence should be addressed.…”

“…3,6,27 The binding of fluorescent ligands has been commonly used for verifying surface functionalization. 14,28 However, these studies have only qualitatively compared silanized and non-silanized surfaces, but have not quantified the fluorescent intensity of the resulting layers. 20,[29][30][31] Fluorescence Recovery after Photobleaching (FRAP) has been used previously to characterize lipid coatings on solid surfaces with only a subset of the lipids fluorescently labeled.…”