QSense Sensors

UV/Ozone treatment of PS might result in new, unwanted chemical composition of the surface. Please note that PS is very hydrophobic and that air bubbles are easily formed on the surface when working with water-based solutions. To reduce the risk of bubble formation, make sure to degas the solutions and to preheat them when working at temperatures above RT. It is also possible to pre-wet the sensor surfaces with ethanol and then replace ethanol with the water-based solution.

Short stranded poly ethylene glycol (PEG) thiols creating mixed self assembled monolayers exposing biotin groups.

-22 ± 3 Hz (a monolayer) of streptavidin in a robust manner for incorporation of different biotinylated proteins

No non-specific binding detected when incubated in fetal bovine serum with protein concentration ~ 40 mg/ml for 30 min

The sensors should be mounted into the instrument directly from the box without prior cleaning since this can affect the adsorbed thiol monolayer. It is sufficient to rinse with water/ buffer in situ before measuring.

Microfibrillated cellulose, also referred to as nanofibrillar cellulose in literature

20-50 nm

Up to several µm

The sensor is delivered in inert atmosphere. Store in a cool, dry place out of light.

Please note that cellulose is a natural material, and minor variations between batches with respect to structure and composition may occur. If the sensors are monitored in water, there will be some initial swelling of the cellulose, which will level out. The cellulose sensor will undergo enzymatic hydrolysis upon treatment with cellulase.

Stable in water and mild buffers between pH 5,0 - 8,0. Not stable in methanol, ethanol, chloroform, strong oxidizing and reducing agents. There is no guarantee that the coating will be stable under all experimental conditions.

70 °C

Stable baseline in air and deionized water in 22 °C. There is no guarantee that the coating will be stable under all experimental conditions.

Cobalt is prone to oxidize in an oxidizing environment. During oxidation process, the top- most layers of cobalt will transform from metal to metal oxide. Since the oxidized layer has poor adhesion to the parent material, this will result in removal of oxidized layer during QCM-D measurement in an oxidizing environment. In the QCM-D signal, this will be shown as a linear drift that needs to be taken into consideration for each specific application.
XPS elemental analysis revealed a pure metal XPS signal after removal of top layer.

Stable in deionized water and aqueous buffers at room temperature for one hour

Stable in deionized water and aqueous buffers at room temperature for one hour

Ti, suitable for electrochemistry applications

Iron (Fe)* 

< 2 nm RMS

QSense sensors are intended for one-time use only. Handle carefully with a pair of tweezers

Delivered in inert packaging. Store in a cool, dry place out of light. Store preferably in inert packaging for reduce of oxidation

Sensor will be stable at least 8 months from delivery

If oxidation is not desired, avoid oxidation agents. Also, avoid strong acids like concentrated nitric acid and sulphuric acid

Store in a dry and oxygen free environment to avoid rusting/oxidation

Stable baseline in air and deionized water in 22 °C. There is no guarantee that the coating will be stable under all experimental conditions

Moderately stable in deionized water and aqueous buffers at room temperature for one hour.

Platinum (Pt)

< 2 nm RMS

QSense sensors are intended for one-time use only. Handle carefully with a pair of tweezers

Store in a cool, dry place out of light.

Sensor will be stable at least 12 months from delivery

Do not expose to Aqua regia since that would dissolve platinum. Platinum also reacts with fluorine

Stable baseline in air and deionized water in 22 °C. There is no guarantee that the coating will be stable under all experimental conditions

Do not expose to strong acids (e.g. HF) or bases (NaOH)

Stable baseline in air and deionized water in 22 °C. There is no guarantee that the coating will be stable under all experimental conditions

Stable baseline in air and deionized water in 22 °C. There is no guarantee that the coating will be stable under all experimental conditions

Stable in deionized water and aqueous buffers at room temperature for one hour.

Due to sensor electrode nature do not expose sensor to strong acids and bases. There is no guarantee that the coating will be stable under all chemical treatments and/or experimental conditions.

Tungsten is prone to oxidize in an oxidizing environment. During oxidation process, the top- most layers of tungsten will transform from metal to metal oxide. Since the oxidized layer has poor adhesion to the parent material, this will result in removal of oxidized layer during QCM-D measurement in an oxidizing environment. In the QCM-D signal, this will be shown as a linear drift that needs to be taken into consideration for each specific application.
XPS elemental analysis revealed a pure metal XPS signal after removal of top layer.