Physical insights from the Frumkin isotherm applied to electrolyte gated organic transistors as protein biosensors

Abstract

Label free biosensors based on electrolyte gated organic transistors (EGOTs) are ultra-sensitive and versatile sensing devices. The dose curve represents the change of the sensor signal as a function of...

Monitoring DNA Hybridization with Organic Electrochemical Transistors Functionalized with Polydopamine

“…We calculated a theoretical limit of detection (LOD) of ≈100 × 10 −15 m , by adding to the current when [fc‐target] = 0 m the standard deviation multiplied by 3. As recently proposed by our group, [ 45 ] we fit the Frumkin isotherm to the dose curve to gain insight into the thermodynamics of fc‐target/probe hybridization. To this end, we first calculated the surface coverage θ = S / S max by assuming S max to be 5% higher than the highest observed S value.…”

“…The absence (or modest) of V GS modulation suggests that we are mostly observing the response due to the change of channel conductivity because of the change of the electrochemical potential of the electrolyte, due to the gate functionalization. [ 45 ]…”

Organic Bioelectronics Development in Italy: A Review

“…The application of different materials, geometries and fabrication techniques, together with a deeper understanding of device physics, allows for the tailoring of the device performances to the specific applications, reaching unprecedented results. The Italian production in this field reflects a generalized trend, with the exploration of materials ranging from small molecules and polymeric OSC [ 39 , 53 , 54 , 55 , 56 ], to polymeric OMIECs [ 57 , 58 , 59 ]. The use of OSCs or OMIECs gated via an electrolyte has proven to be a successful configuration for applications in bioelectronics [ 60 ].…”

“…From a technological point of view, fabrication techniques derived from silicon technology are exploited [ 39 , 57 , 63 , 64 , 65 , 66 ], as well as 2D and 3D printing technologies [ 7 , 54 , 67 , 68 , 69 , 70 , 71 ]. Moreover, increasingly accurate models have been developed in order to better understand the physical mechanisms governing the device operations, both in terms of the electrolyte-gating working mechanisms and in terms of the biosensor’s response to a given analyte [ 55 , 56 , 59 , 72 ]. In the following subsections, the cutting-edge progress achieved by the Italian Organic Bioelectronics community concerning the fabrication and modelling of novel organic transistor-based sensors will be described.…”

“…Physical modelling has emerged from several points of view as a fundamental aspect in the evolution of integrated bioelectronic devices. The design of microfluidic cartridges aimed at avoiding device contaminations [ 13 , 90 ], the description of physical mechanisms involved in EGOT operations [ 59 , 72 ], the proper co-design of an electronic device and functionalization strategy [ 55 ] and the correct interpretation of a biosensor’s response at different analytes [ 53 , 56 ]; these are all fundamental parts of the device engineering benefiting from the development of more accurate models. In the following section, we will focus on the last three aspects, skipping the design of microfluidic devices.…”