Single-Choice Kapitel 2

For potentiometric sensors the sensor signal linearly depends on the ion concentration.

For potentiometric sensors the sensor signal logarithmically depends on the ion concentration.

For potentiometric sensors the potential-determining process occurs at the phase boundary of the reference electrode to have a stable voltage.

For potentiometric sensors field-effect capacitors represent a miniaturized subclass.

The potentiometric sensors the main potential difference takes place inside the Guoy-Chapman layer.

For field-effect capacitors as biosensors the change of the space-charge capacitance is read-out as (bio-)sensor signal.

For field-effect capacitors as biosensors the change of the accumulation capacitance is read-out as (bio-)sensor signal.

For field-effect capacitors as biosensors the value of the accumulation capacitance is influenced by the change of the space-charge capacitance.

For field-effect capacitors as biosensors the ConCap mode enables dynamic monitoring of potential changes at the gate surface.

For field-effect capacitors as biosensors the direction of potential shift is independent in the charge sign of adsorbed species.

For field-effect capacitors as biosensors the gate insulator can already be applied as pH-sensitive transducer layer.

Capacitive field-effect biosensors for pH/ion sensing deliver a positive charging of the sensor surface > pH_pzc and a negative charging for < pH_pzc.

Capacitive field-effect biosensors for pH/ion sensing deliver a negative charging of the sensor surface < pH_pzc and a positive charging for > pH_pzc.

Capacitive field-effect biosensors for pH/ion sensing deliver a negative charging of the sensor surface > pH_pzc and a positive charging for < pH_pzc.

Capacitive field-effect biosensors for pH/ion sensing deliver a positive charging of the sensor surface < pH_pzc and a negative charging for > pH_pzc.

Capacitive field-effect biosensors for pH/ion sensing utilize ionophore-containing membranes for pH sensing and dielectric gate insulators for ion sensing.

For ion sensing with field-effect capacitors the theoretical Nernstian sensitivity of monovalent and bivalent ions at room temperature is 59 mV/dec and 29.5 mV/dec.

For ion sensing with field-effect capacitors the theoretical Nernstian sensitivity of monovalent and bivalent ions at room temperature is 59 mV/dec and 108 mV/dec.

For ion sensing with field-effect capacitors the theoretical Nernstian sensitivity does not depend on the charge number of the ion.

For ion sensing with field-effect capacitors the higher the charge number, the higher will be the overall sensitivity.

For ion sensing with field-effect capacitors the thickness of the sensor membrane will have influence on the sensor signal.

Enzyme-based capacitive field-effect biosensors are relying on an indirect detection principle, focussing on biocatalytic products

Enzyme-based capacitive field-effect biosensors often measure either a pH increase or a pH decrease.

Enzyme-based capacitive field-effect biosensors often measure neither pH decrease nor a pH increase, pH must be always stable (see reference electrode).

Enzyme-based capacitive field-effect biosensors require immobilized enzymes on top of their gate surface, where sensor stability and sensitivity can be improved by nanoparticle “assistance”.

Enzyme-based capacitive field-effect biosensors allow additionally nanoparticle monitoring via ConCap measurement mode.

Enzyme-based capacitive field-effect biosensors can be utilized as a (simple) digital biosensor.

Label-free DNA sensing needs, for example, fluorescent markers.

Label-free DNA sensing will measure the intrinsic positive charge of DNA molecules.

Label-free DNA sensing allows only DNA charge detection inside the Debye length.

Label-free DNA sensing prefers having single-stranded DNA immobilization flat on the gate surface.

Label-free DNA sensing can be hardly influenced by the ionic strength of the analyte.

Label-free DNA sensing can utilize negatively charged macromolecules to attract the single-stranded DNA.

Label-free DNA sensing prefer nonspecific adsorption of proteins to have higher sensitivity.

Capacitive field-effect biosensors can be combined with magnetic actuators.

Capacitive field-effect biosensors detect charge changes near the gate surface.

Capacitive field-effect biosensors enable multi-analyte detection.

Capacitive field-effect biosensors possess signal behaviour that also depends on the isoelectric point of adsorbed molecules.

Capacitive field-effect biosensors cannot only detect single-stranded DNA during hybridizazion, but also directly double-stranded DNA.

Capacitive field-effect biosensors should measure in low-ionic strength analytes to have higher sensitivity in terms of charging.

Capacitive field-effect biosensors have similar gate structure such as a conventional field-effect transistor.

Capacitive field-effect biosensors always need an additional reference electrode.