Bioinspired Repellent Pipette Tips with Low Retention Properties Prevent Contamination in Handling Biological Samples

Abstract Cross-contamination of biological samples during handling and preparation, is a major issue in laboratory setups, leading to false-positives or false-negatives. Sample carryover residue in pipette tips contributes greatly to this issue. Most pipette tips on the market are manufactured with hydrophobic polymers that are able to repel high surface tension liquids, yet they lack in performance when low surface tension liquids are involved. This presents an obstacle for pipette tips as inaccuracies and loss in precision arise when low surface tension liquids such as viscous oils are pipetted. Here we propose the use of lubricant-infused surface (LIS) technology to achieve omniphobic properties in pipette tips. Using a versatile and simple design, the inner lumen of commercially available pipette tips was coated with a fluorosilane (FS) layer using chemical vapor deposition (CVD). We show that after lubricating the tips through simply pipetting up and down a fluorinated lubricant, the surface free energy of the tips drastically decreased enabling them to attain low retention properties. Contact angle measurements reveals that the treated pipette tips have enhanced omniphobic properties. The repellent behavior of the lubricant-infused pipette tips against physical adsorption is investigated through pipetting a food coloring dye as well as human blood samples and are compared to the untreated tips. The results show significantly less amount carryover residue when the lubricant-infused tips are utilized compared to commercially available ones.

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Influence of plasma treatment on SiO2/Si and Si3N4/Si substrates for large-scale transfer of graphene

Scientific Reports ◽

10.1038/s41598-021-92432-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

R. Lukose ◽

M. Lisker ◽

F. Akhtar ◽

M. Fraschke ◽

T. Grabolla ◽

...

Keyword(s):

Large Scale ◽

Oxygen Plasma ◽

Chemical Vapor ◽

Limiting Factors ◽

Adhesion Properties ◽

Si Substrates ◽

Wetting Contact Angle ◽

Angle Measurements ◽

Chemical Vapor Deposited ◽

Contact Angle Measurements

AbstractOne of the limiting factors of graphene integration into electronic, photonic, or sensing devices is the unavailability of large-scale graphene directly grown on the isolators. Therefore, it is necessary to transfer graphene from the donor growth wafers onto the isolating target wafers. In the present research, graphene was transferred from the chemical vapor deposited 200 mm Germanium/Silicon (Ge/Si) wafers onto isolating (SiO2/Si and Si3N4/Si) wafers by electrochemical delamination procedure, employing poly(methylmethacrylate) as an intermediate support layer. In order to influence the adhesion properties of graphene, the wettability properties of the target substrates were investigated in this study. To increase the adhesion of the graphene on the isolating surfaces, they were pre-treated with oxygen plasma prior the transfer process of graphene. The wetting contact angle measurements revealed the increase of the hydrophilicity after surface interaction with oxygen plasma, leading to improved adhesion of the graphene on 200 mm target wafers and possible proof-of-concept development of graphene-based devices in standard Si technologies.

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Zwitterionic molecule layer for inhibiting microbial corrosion of copper alloy

Anti-Corrosion Methods and Materials ◽

10.1108/acmm-12-2016-1744 ◽

2018 ◽

Vol 65 (1) ◽

pp. 46-52

Author(s):

Fengling Xu ◽

Zhenghui Qiu ◽

Ri Qiu ◽

Jiadong Yang ◽

Cunguo Lin

Keyword(s):

Electrochemical Impedance ◽

Chemical Vapor ◽

Attenuated Total Reflectance ◽

Microbial Corrosion ◽

Content Type ◽

Sulfate Reducing ◽

Angle Measurements ◽

Static Contact ◽

Contact Angle Measurements ◽

Reducing Bacteria

Purpose For mitigating biocorrosion induced by sulfate-reducing bacteria (SRB) in seawater, the zwitterionic molecule layer (ZML) of poly (sulfobetaine methacrylate) is grafted onto B10 surface by chemical vapor deposition and surface-initiated atom transfer radical polymerization. Design/methodology/approach Energy-dispersive spectroscopy-attenuated total reflectance Fourier transform infrared spectroscopy and static contact angle measurements are used to characterize the as-formed layer. Findings After surface modification, B10 can significantly reduce SRB adhesion, demonstrating the good antifouling property. Further, the biocorrosion inhibition is investigated by potentiodynamic polarization and electrochemical impedance spectroscopy, indicating that ZML exhibits high resistance to biocorrosion with inhibition efficiency of approximately 90 per cent. Originality/value ZML performs a dual feature, i.e. antifouling film and corrosion inhibitor, for the biocorrosion inhibition.

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Hydraulic Performance Modifications of a Zeolite Membrane after an Alkaline Treatment: Contribution of Polar and Apolar Surface Tension Components

Advances in Materials Science and Engineering ◽

10.1155/2015/524259 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Patrick Dutournié ◽

Ali Said ◽

T. Jean Daou ◽

Jacques Bikaï ◽

Lionel Limousy

Keyword(s):

Surface Tension ◽

Alkaline Treatment ◽

Contact Angles ◽

Van Der Waals Interactions ◽

Zeolite Membrane ◽

Polar Component ◽

Material Surface ◽

Hydraulic Permeability ◽

Angle Measurements ◽

Contact Angle Measurements

Hydraulic permeability measurements are performed on low cut-off Na-mordenite (MOR-type zeolites) membranes after a mild alkaline treatment. A decrease of the hydraulic permeability is systematically observed. Contact angle measurements are carried out (with three polar liquids) on Na-mordenite films seeded onto alumina plates (flat membranes). A decrease of the contact angles is observed after the alkaline treatment for the three liquids. According to the theory of Lifshitz-van der Waals interactions in condensated state, surface modifications are investigated and a variation of the polar component of the material surface tension is observed. After the alkaline treatment, the electron-donor contribution (mainly due to the two remaining lone electron pairs of the oxygen atoms present in the zeolite extra frameworks) decreases and an increase of the electron-receptor contribution is observed and quantified. The contribution of the polar component to the surface tension is attributed to the presence of surface defaults, which increase the surface hydrophilicity. The estimated modifications of the surface interaction energy between the solvent (water) and the Na-mordenite active layer are in good agreement with the decrease of the hydraulic permeability observed after a mild alkaline treatment.

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