Publications

@article{Somekh2024-oz,

title = {Common framework for surface plasmon binding and voltage sensing  and microscopy with transmission line representation},

author = {Michael G Somekh and Karen Regules-Medel and Sidahmed A Abayzeed},

doi = {10.1364/JOSAA.534360},

year  = {2024},

date = {2024-11-01},

urldate = {2024-11-01},

journal = {J. Opt. Soc. Am. A Opt. Image Sci. Vis.},

volume = {41},

number = {11},

pages = {C90\textendashC98},

publisher = {Optica Publishing Group},

abstract = {Surface plasmon imaging and sensing is a well-established and 

 important technology for the detection of minute binding events 

 in, for instance, antibody/antigen reactions. More recently it 

 has been realized that surface plasmon effects can be used to 

 measure voltages as well as electrical impedance. At first sight 

 the physical mechanisms for binding and voltage sensing appear 

 very different; however, we develop a transmission line and 

 impedance representation of the sensing process which clearly 

 shows that binding and voltage sensing can be conveniently 

 represented in a common framework. Our transmission line model 

 shows graphically how the gold layer amplifies reflectivity 

 changes resulting in optimum sensitivity at around 48 nm gold 

 thickness. The other elegant feature of this representation is 

 that the model clearly shows the role of the change in amplitude 

 and phase in the sensing process; indeed it reveals their 

 relative contribution to the output of the sensor. The graphical 

 representation is also very suggestive of a model to quantify 

 the performance of different detection strategies. This model 

 provides a framework to describe these strategies without 

 reference to any specific noise mechanisms. The results of the 

 model definitively support previous assertions that phase 

 imaging gives better sensitivity compared to intensity 

 measurement. Moreover, we show that measurement of the complex 

 amplitude containing both amplitude and phase of the detected 

 signal performs even better than phase only detection. This 

 opens the way for further enhancements of detection sensitivity.},

keywords = {localised surface plasmon resonance, voltage sensing},

pubstate = {published},

tppubtype = {article}

}